Allez, avec un peu de chances, j’aurai peut-être le plaisir d’offrir un lot de consolation à quelques innovateurs solidaires français ? Quelques équivalents-temps plein d’ingénieurs et consultants informaticiens, gratuitement, pour votre projet d’intérêt général, ça vous tente ?

Au passage, je remercie Monsieur D., de Chambéry d’Albertville, qui a bien voulu me signaler cette initiative de Google que j’avais loupée. Monsieur D. est parfois timide alors il m’avait contacté par mail plutôt que via un commentaire sur ce blog. ;-)

En effet, dans le cadre de ma nouvelle entreprise, je propose mes services professionnels à tout projet informatique d’intérêt général: je fournis (à coût zéro, cf plus bas) mes compétences en tant que directeur de projets informatiques innovants ainsi que l’accès aux compétences de très nombreux autres ingénieurs informaticiens, sur leur temps de travail. Vous voulez des compétences d’ingénieurs informaticiens pour rendre le monde meilleur ? En voila !

Notez que je ne place, a priori, aucune limitation de thème ou de domaine : lutte contre la pauvreté, recherche scientifique, défense de l’environnement, santé, handicap, protection de l’enfance, etc. peu importe du moment que ce projet va vraiment dans le sens de l’intérêt général et de l’utilité publique (cf. ci-dessous).

Les conditions à remplir

Pour que mon entreprise puisse intervenir, votre projet informatique doit absolument :

• être “d’intérêt général”, c’est-à-dire être porté par un organisme ayant le droit, en France, d’émettre des reçus fiscaux en échange des dons reçus (mécénat)
• ne pas être un tout petit projet: il doit nécessiter, de la part des mécènes, au moins 1 ingénieur à temps plein
• être porté par une équipe déjà active : je peux fournir entre 2 fois et 5 fois le temps que vous passez déjà sur le projet, en tant que bénévoles ou salariés ; si vous ne travaillez pas déjà sur le projet, je ne peux rien faire (0 fois 2 égal 0 !)
• être un projet qui en vaut vraiment la peine: avoir un véritable impact social, direct ou indirect, une utilité clairement mesurable et motivante, répondre à un défi de société à petite ou à grande échelle, être source, levier ou moteur de changement pour la société…
• ne pas nécessiter de présence physique importante en dehors de la région parisienne (je démarre petit et près de chez moi, même si je suis un adepte du travail à distance et des “conf call”), bref être plutôt localisé près de Paris

Qu’est-ce qu’un projet informatique d’intérêt général ?

Un projet informatique est d’intérêt général si il est porté par un organisme bénéficiant du régime fiscal français du mécénat. Ah, ah… mystère, qu’est-ce que c’est que ce truc ? La loi française d’août 2003 sur le mécénat reste mal connue mais elle représente une source de revenus importante pour les organismes d’intérêt général. Plusieurs types d’organismes répondent à ce critère. Pour faire simple, il peut s’agir d’une association loi 1901 :

• à but non lucratif : elle ne reverse pas de TVA, ne paye pas d’impôts sur les sociétés, a des administrateurs et un bureau bénévoles et désintéressés, ne vient pas concurrencer des entreprises commerciales ou alors elle le fait à des prix beaucoup plus bas que le marché et principalement pour un public défavorisé et sans “pratiques commerciales” (publicité, …) ; demandez l’avis d’un comptable si besoin
• et dont l’objet est à caractère philanthropique, éducatif, social, humanitaire, sportif, familial, culturel, artistique, environnemental, culturel, littéraire, scientifique…
• et dont les activités ne bénéficient pas à un cercle restreint de personnes (contrairement aux syndicats ou aux associations d’anciens élèves d’une école par exemple …)

Au besoin, une association loi 1901 peut être facilement créée pour porter ce projet (statuts et déclaration en préfecture) et réunir les conditions de l’intérêt général. Il n’y a pas de condition d’ancienneté ni de taille de l’association. Il n’y a pas non plus forcément besoin d’obtenir un agrément administratif (comme ce serait le cas pour les associations “reconnues d’utilité publique”, ce qui est une reconnaissance très difficile à obtenir de nos jours).

Pour en savoir plus sur la notion d’intérêt général, je vous invite à consulter le site mécénat du ministère de la culture ainsi que les explications de l’Association pour le Développement du Mécénat Industriel et Commercial (ADMICAL).

Comment je peux aider, en pratique ?

Si vous consacrez déjà du temps à votre projet, je peux donc démultiplier cet effort.

Exemple: avec 4 autres bénévoles, vous consacrez au moins, chacun, une journée par semaine à votre projet (soit un équivalent temps plein, 5 jours de travail par semaine), alors je peux vous fournir, en complément, l’équivalent de 2 ingénieurs à temps plein (10 jours de travail par semaine), voire plus si votre projet est très simple à gérer.

Cette aide prendra la forme de:

• un accompagnement permanent par mon entreprise : au moins une demi-journée d’assistance et de conseil par semaine, en fonction du volume de votre projet ; plus un service de représentation et de suivi de votre projet auprès des entreprises mécènes,
• des interventions individuelles d’un grand nombre (50, 100, 200…?) de professionnels de l’informatique, ingénieurs, techniciens ou consultants, pour des durées variables et parfois courtes (par exemple une semaine), sur leur temps de travail,
• la possibilité de renforcer votre équipe bénévole par les contributions ultérieures de certains de ces intervenants sur leur temps libre (constitution éventuelle d’une communauté à la mode open source si votre projet s’y prête)
• l’accès à un système d’information sécurisé sur le Web pour gérer votre projet, vos intervenants, vos relations avec les mécènes et automatiser la gestion de toute la paperasse administrative qui va avec (contrats, convention de mécénat, reçus fiscaux, …)

Comment ça marche ?

Je créé actuellement une entreprise à vocation sociale dont l’objectif est de fournir aux innovateurs sociaux les mêmes moyens informatiques que ceux dont disposent les entreprises les plus modernes. Mon activité s’appuie sur le mécénat de sociétés de services en informatique (SSII) qui s’engagent dans des démarches de “développement durable” (ou, plus exactement, de “responsabilité sociale de l’entreprise”). Elles souhaitent faire du mécénat de compétences en informatique par mon intermédiaire : faire don du temps de travail de leurs ingénieurs et consultants sous la forme d’une prestation de service gratuite gérée via le Web. J’appelle ça “faire du wecena” (Wecena, c’est le nom de ma boîte !).

Le financement de cette aide est indirectement assuré à 100% par l’Etat français, grâce à la loi sur le mécénat des entreprises. En effet, l’Etat accorde une réduction d’impôts importante à toute entreprise qui décide d’aider concrètement un organisme d’intérêt général (don d’argent, don en nature, don de compétences et temps de travail…). Les SSII mécènes que je rencontre sont prêtes à se lancer dans l’aventure en proposant à leurs ingénieurs de faire avancer votre projet pendant ces périodes de temps que l’on appelle l’”inter-contrat” (ou intercontrat ou “période de stand-by” ou …) : il s’agit de ces périodes de quelques jours à quelques mois qui commencent lorsque l’ingénieur termine un projet pour un client et n’est pas encore affecté à un autre projet pour un nouveau client.

Cela impose une contrainte importante dans la gestion de votre projet: les ingénieurs réalisant la prestation de service vont se relayer à un rythme très rapide, certains ne seront présents que 48H tandis que d’autres seront disponibles 2 ou 3 mois dans l’année. La durée moyenne d’intervention individuelle se situe quelque part entre une semaine et un mois (selon le métier de l’intervenant et l’état du marché de l’informatique, et aussi selon la politique du mécène). C’est le rôle de mon entreprise que de vous aider à gérer cette contrainte. Notez que cette contrainte a également quelques avantages : si votre projet est suffisament simple et “découpable” en petites tâches (à l’aide de méthodes et d’outils de gestion adaptées, que je vous fournis), vous aurez ainsi l’occasion de proposer votre cause à une multitude d’intervenants que vous pourrez recruter en autant de bénévoles potentiels une fois leur mission de wecena terminée. C’est par exemple le cas de projets portant sur de l’initiation à l’informatique, de l’animation d’atelier informatique auprès de personnes défavorisées, d’interventions multiples d’installation de PC ou de réseau local… Pour des projets plus complexes (développement, conseil, …), votre implication est plus importante et le wecena ne peut pas représenter plus de 2 fois le temps que vous y consacrez déjà.

Quelques exemples de projet

Pour vous aider à vous faire une idée du type de projet qui peuvent bénéficier du wecena, voici quelques exemples de projets que j’ai déjà présenté à des mécènes :

• conception et réalisation d’un logiciel innovant pour faciliter l’utilisation du clavier et de la souris par des personnes ayant un handicap moteur
• amélioration de l’infrastructure informatique d’une ONG travaillant dans la lutte contre l’exclusion: remplacement d’un parc de postes de travail, interventions d’administration système sur des serveurs de fichiers et d’application, …
• déploiement d’un progiciel de reporting financier sur des prestations de services en mode projet pour une association recevant d’importantes subventions publiques
• refonte d’applicatifs Web pour la gestion documentaire, la gestion des relations et contacts et la gestion des adhésions pour une association Internet dans le domaine de la famille et de la protection de l’enfance
• création d’un blog par un écrivain public d’une ONG franco-africaine pour sensibiliser des étudiants français au problématiques du développement Nord-Sud
• assistance à la webisation d’un système de gestion d’établissements de santé pour une association du secteur sanitaire et social
• initiations informatiques et formation aux logiciels internes pour des bénévoles retraités d’une association humanitaire

Ce ne sont que quelques exemples pour vous donner le ton. Aucun de ces projets n’a encore démarré.

Avertissement

Mon entreprise en est encore à une phase de démarrage et d’expérimentation. Je ne peux actuellement vous garantir ni que votre projet en particulier sera sélectionné par un mécène (les projets les plus solides et les plus ambitieux auront plus de chances bien entendu) ni même de pouvoir démarrer mon accompagnement tout de suite. En effet, l’aide que je peux vous apporter est en soi un projet (créer une entreprise…) : j’y crois énormément puisque j’ai quitté mon employeur précédent pour me lancer dans cette aventure, et j’y consacre tout mon temps et mes compétences. Mais, ceci dit, démarrer ce genre d’entreprise sociale innovante prend du temps et représente aussi une part de risque, d’incertitude, bref d’aventure… Le premier projet que j’accompagnerai pourrait démarrer fin 2008 (si les étoiles s’alignent comme prévu) ou au plus tard début 2009 (si j’ai moins de chance). Les mécènes que je rencontre sont déjà sur le pied de guerre et ont déjà commencé à examiner les projets informatiques que je leur présente. Certains ont déjà exprimé leur préférence et se mettent en ordre de bataille… En croisant les doigts, j’espère qu’un premier projet pourrait démarrer peu après la rentrée scolaire 2008.

Pour participer à l’aventure…

Vous connaissez une équipe qui porte un projet informatique d’intérêt général et a besoin de temps d’informaticiens pour aller plus loin et plus vite ? Faites-lui suivre l’adresse de cet article !

Votre projet répond aux conditions présentées ci-dessus ?  Pour vous en assurer, posez la question via un commentaire ci-dessous ou contactez-moi directement par email à l’adresse suivante: projets (chez) wecena (point) com ou bien encore à mon adresse de blogueur: sig (chez) akasig (point) org. Le site Web de mon entreprise ne devrait pas ouvrir ses portes avant le démarrage du premier projet. En attendant, c’est ici que ça se passe. Vous avez des conseils à me donner, des avis ou des contacts à partager ou des suggestions à faire ? Ils seront bienvenus: je vous invite également à utiliser la fonction commentaires de ce blog.

IEML: not another layer on top of the SW cake

IEML is proposed as an alternative to SW ontologies. In SW, the basic technology is URI (Uniform Resource Identifier) which uniquely (and hopefully permanently) identify concepts (”resources”). Triples then combine these URIs into assertions which then form a graph of meaning that is called an ontology. IEML introduces identifiers which are not URIs. The main difference between URIs and IEML identifiers is that IEML identifiers are semantically rich. They carry meaning. They are meaningful. From a given IEML identifier, one could derive some (or ideally all?) of the semantics of the concept it identifies. Indeed these identifiers are composed of 6 semantic primitives. These 6 primitives are Emptiness, Virtual, Actual, Sign, Being, Thing (E,V,A,S,V and T) and were chosen to be as universal as possible, i.e. not dependent on any specific culture or natural language. The IEML grammar is a way to combine these primitives and logically build concepts with them (also using the notion of triples-based graphs). These primitives are comparable to the 4 bases of DNA (A,C,T and G) that are combined into a complex polymer (DNA) : with a limited alphabet, IEML can express an astronomically huge number of concepts in the same way the 4 letters-alphabet of DNA can express a huge number of phenotypes.

Meaningness of identifiers

When I realized that the meaningful IEML identifiers are similar in their role to URIs, my first reaction was of being horrified. I have struggled for years against “old-school” IT workers who tend to rely on database keys for deriving properties of records. In a former life in the IT department of big industrial corporation, I was highly paid to design and impose a meaningless unique person identifier in order to uniquely and permanently identify the 200 000 employees and contractors of that multinational company in its corporate directory. The main superiority in meaningless identifiers is probably that they can be permanent: you don’t have to change the identifier of an object (of a person for instance) when some property of this object changes over time (the color of the hair of the person, or Miss Dupont getting married and getting called Misses Durand while still keeping the same corporate identifier).

The same is true for URIs whenever it is feasible: if a given resource is to change over time, its URI should not be dependent on its variable property (http://someone.com/blond/big/MissDurand having to change into http://someone.com/white/big/MissesDupont is a bad thing).

The same may not be true when concepts (not people) are to be identified. Concepts are supposed to be permanent and abstract things with IEML (as in the SW I guess). If some meaningful semantic component of a given concept changes then… it’s no longer the same concept (even though we may keep using the same word in a natural language in order to identify this derived concept).

In the old days, IT workers used to introduce meaning in identifiers so that (database) records could more easily be managed by humans, especially during tasks like visually classifying or sorting records in a table or getting an immediate overview of what a given record is about. But this often got seen as a bad practice when the cost of storage (having specific fields for properties that used to be stored as part of a DB key) and the cost of computation (getting a GUI for querying/filtering a DB based on properties) got lower. More often that not, the meaningful key was not permanent and this introduced perverse effects including having to assign a new key to a given record when some property changed or managing human errors when the properties “as seen in the key” were no longer in sync with the “real” properties of the record according to some field.

That’s probably part of the rationale behind the best practices in URI design and web architecture: an URI should be as permanent as possible I guess, in order not to change when the properties of a resource it identifies change over time. Thus web architectures are made more robust to time.

With IEML, we are back to the ol’times of meaningful identifiers. Is it such a bad thing ? Probably not because the power of IEML relies in the meaningness of these identifiers which allow all sorts of computational operations on the concepts. Anyway, that’s probably one of the biggest basic difference between IEML and the SW ontologies.

Matching concepts with IEML

Another aspect of IEML struck me yesterday: IEML gives no magic solution to the problem of mapping (or matching) concepts together. In the SW universe, there is this recurring issue of getting two experts or ontologies agree on the equivalence of 2 resources/concepts: are they really the same concept expressed with distinct but equivalent URIs ? or are they distinct concepts ? How to solve semantic ambiguities ? Unless we get a solution to this issue, the grand graph of semantic data can’t be universally unified and people get isolated in semantic islands which are nothing more than badly interconnected domain ontologies. This is called the problem of semantic integration,  ontology mapping, ontology matching or ontology alignment.

A couple of years ago, I hoped that IEML would solve this issue. IEML being such a regular and to-be-universal language, one could project any concept onto the IEML semantic space and obtain the coordinates (identifier) of this concept in this space. A second person or expert or ontology could also project its own concepts. Then it would just be a matter of calculating the distance between these points in the IEML space. (IEML provides ways of calculating such distances). And if the distance was inferior to some threshold, 2 concepts could then be considered as equivalent for a given pragmatic purpose.

But yesterday, I realized that the art of projecting concepts into the IEML space (i.e. assigning an identifier to a concept) is very subjective. Even though a Pierre Levy could propose a 3000-concepts dictionary that assigns IEML coordinates (identifiers) to concepts that are also identified by a short natural language sentence (like in a classic dictionary), this would not prevent a Tim Berners-Lee to come with a very different dictionary that assigns different coordinates to the same described concepts. Thus the distance between a Pierre-Levy-based IEML word and a TBL-based IEML word would be … meaningless.

In the SW, there is a basic assumption that anyone may come with a different URI for the same concepts and the URIs have to be associated via a “same as” property so that they are said to refer to the very same concept. When you get to bunches of URIs (2 ontologies for instance), you then have to match these URIs which refer to the same concepts. You have to align these ontologies. This can be a very tedious, manual and tricky process. The SW does not unify concepts. It only provides a syntax to represent and handle them. Humans still have to interprete them and match them together when they want to communicate with each other and agree on the meaning that these ontologies carry.

The same is more or less true with IEML. With IEML, identifiers are not arbitrarily defined (meaningful identifiers) whereas SW URIs are almost arbitrarily defined (meaningless identifiers). But the meaningful IEML identifiers only carry human meaning if they refer to the same (or similar) human/IEML dictionary.

Hence it seems to me that IEML is only valuable if some consensus exists about how to translate human concepts into the IEML space. It is only valuable to the extent that there is some universally accepted IEML dictionary. At least for basic concepts (primitives and simple combinations of IEML primitives). The same is true in the universe of SW technologies and there are some attemps at building “top ontologies” that are proposed as shared referentials for ontology builders to align their own ontologies with. But the alignment process, even if theoretically made easier with the existence of these top ontologies is still tricky, tedious and costly. And the critical mass has not been reached in sharing the use of such top ontologies. There is no top consensus to refer to.

Pierre Levy proposes a dictionary of about 3000 IEML words (identifiers) that represent almost all possible low-level combinations of IEML primitives. He invites people to enhance or extend his dictionary, or to come with their own dictionaries. Let’s assume that only minor changes are made to the basic Pierre Levy dictionary. Let’s assume that several conflicting dictionary extensions are made for more precise concepts (higher-level combinations of IEML primitives) . Given the fact that these conflicting extensions still share a basic foundation (the basic Pierre Levy dictionary), would the process of comparing and possibly matching IEML-expressed concepts be made easier ? Even though IEML does not give any automagical solution to the problem of ontology mapping, I wonder whether it makes things easier or not.

In other words, is IEML a superior alternative to SW ontologies ?

Apples and bananas

Yesterday, someone asked: “If someone assigns IEML coordinates to the concept of bananas, how will these coordinates compare to the concept of apples ?” The answer did not satisfy me because it was along the lines of : “IEML may not be the right tool for comparing bananas to apples.”. I don’t see why it would be more suitable for comparing competencies to achievements than for comparing bananas to apples. Or I misunderstood the answer. Anyway…

Pierre Levy made much effort in describing the properties of his abstract IEML space so that IT programmers could start programming libraries for handling and processing IEML coordinates and operations. There even is a programming language being developped that allows semantic functions and operations to be applied to IEML graphs and to allow quantities (economic values, energy potentials, distances) to flow along IEML-based semantic graphs. Hence the name of Information Economy.

So there are (or will soon be) tools and services for surviving in the IEML space. But I strongly feel that there is a lack of tools for moving back and forth between the world of humans and the IEML space. How would you say “bananas” in IEML ? Assuming this concept is not already in a consensual dictionary.

As far as I understand the process of assigning IEML coordinates to the concept of “bananas” is somehow similar to the process of guessing the “right” (or best?) chinese ideogram for bananas. I don’t speak chinese at all. But I imagine one would have to combine existing ideograms that would best describe what a banana is. For instance, “bananas” could be written with a combination of the ideograms that mean “fruits of herbaceous plant cultivated throughout the tropics and grow in hanging clusters“. It could also be written with a combination of the ideograms that mean “fruits of the plants of the genus Musa that are native to the tropical region of Southeast Asia and Australia.” Distinct definitions of bananas could refer to distinct combinations of existing IEML concepts (fruits + herbaceous plant + hanging clusters + tropics or fruits + plants + genus Musa + Southeast Asia + Australia). Would the resulting IEML coordinates be far away from each other ? Could a machine infer that these concepts are closely related if not practically equivalent to each other ? How dependent would the resulting distance be on conflicts or errors in underlying IEML dictionaries ?

I ended the day with this question in my mind: How robust is the IEML translation process to human conflicts, disagreements and errors ? Is it more robust than the process of building and aligning SW ontologies ? Its robustness seems to me as the main determinent factor of the feasibility of the new collective-intelligence-based civilization Pierre Levy promises. If only there were a paper comparing this process to what the SW already provides, I guess people would realize the value of IEML.

• the “Web-Oriented Architecture” (WOA) concept is a lightweight version of the “Service-Oriented Architecture” concept, in a more Web 2.0 fashion.
• restlets are a Java framework for Web 2.0 applications; they replace servlets API and facilitate the composition of “mashups” or Web applications relying on information collected from other live Web applications; there even is an open source reference implementation that is about to reach maturity and is actively developped

Take-away: beyond theory (ReST), there now are concepts (WOA) and tools (restlets) for building composite Web applications without requiring SOAP, WSDL and the whole bunch of overbloated WS-* standards that come with them.

A nice 10 min long WikiCalc screencast with audio is available here.

In a former life, I was managing a team of web project managers in a multinational industrial corporation. As my boss wanted to get simple-to-update weekly/monthly status report about every project, we had tried using a wiki page per project in order to publish and update those reports. It was tedious and not nicely formatted for a corporate environment. I imagine that a nice immediate use of WikiCalc would be to let small project teams update project status reports on an intranet, including nicely formatted timelines and budget indicators. It would still maintain the update effort at a minimal and convenient level and would preserve the wiki flexibility of linking to the project documentation and resources.

We knew structured wiki pages for managing forms or category schemes. WikiCalc introduces spreadsheet structures while preserving the open and unstructured spirit of wikis. Next steps for future wikis would be to allow semantic structures to be managed the wiki-way, like in some early semantic wiki prototypes. [update: see Danny Ayers blog entries on how WikiCalc could relate to the Semantic Web vision]

Clay Shirky soutient que la gestion d’ontologies n’est pas une sinécure et que les technologies de “social tagging”/”folksonomies” sont une alternative beaucoup plus adaptée à l’Internet que ne l’est la vision du Web Sémantique des spécialistes des ontologies. Selon moi, l’alternative proposée (le social tagging) est bonne mais la critique anti-ontologies est exagérée car je ne pense pas que la vision de Tim Berners-Lee du web sémantique soit autant portée sur une modélisation ontologique top-down des connaissances que l’on veut bien le dire. Bref, pour moi, la solution d’avenir ce serait quelque chose du genre “semantic social tagging”. Cet article est un bon point de départ pour découvrir les folksonomies, comparées à la modélisation ontologique des connaissances.

Sur un ton plus comique, on peut trouver une libre reprise d’un sketch des comiques anglais “Monty Python” qui se moque de l’approche top-down des spécialistes du web-sémantique ; la critique est aisée depuis que Tim Berners Lee a été adoubé chevalier par la reine d’Angleterre… Elle n’en reste pas moins tout à fait amusante et intéressante.

Au passage, je vous suggère une manière simple de se représenter le web sémantique : imaginez que le web devienne non pas simplement un gros document hyper-texte mais également une grosse base de données. Avec le web sémantique, les applicatifs (agents ou non) pourront “librement” traiter des données produites par d’autres applications.

• Ajax is said to be the cross-platform successor to Java… huh… (David, thank you for this pointer)
• Ajax should be ReSTfully considered before use
• Is Ajax ReSTless and dirty ?

While I am mentionning the Representational State Transfer (ReST) architecture style, here are some additional and valuable resources on this topic :

• Do we need a ReST toolkit for application developpers ? What would it look like ?
• NetKernel is claimed to be such a ReSTful toolkit
• A ReSTful toolkit for application developers would be a low cost disruption to the heavyweight SOA products that are (by far) overshooting the market of IT departments in big corporations ; it nicely fits the Christensen model of disruptive innovations

It’s a kind of basic block for building a comparison framework, for building Plone applications that compare stuff (any kind of stuff that exists within your portal, including semantically agregated stuff). Let’s say that your Plone portal is full of descriptions of beers (with many details about all kinds of beers). Then adding a comparator to your portal will let your users give weights to every beer property and rank all the beers according to their personal tastes.

Comparator is based on Archetypes and was built from an UML diagram with ArchgenXML. Comparator fits well in my vision of semantic agregation. I hope you can see how. Comments welcome !

The Daisy project encompasses two major parts: a featureful document repository

Plone is based on an object-oriented repository (Zope’s ZODB) rather than a document oriented repository.

and a web-based, wiki-like frontend.

Plone has its own web-based fronted. Wiki features are provided with an additional product (Zwiki).

If you have different frontend needs than those covered by the standard Daisy frontend, you can still benefit hugely from building upon its repository part.

Plone’s frontend is easily customizable either with your own CSS, with inherting from existing ZPT skins or with a WYSIWYG skin module such as CPSSkin.

Daisy is a Java-based application

Plone is Python-based.

, and is based on the work of many valuable open source packages, without which Daisy would not have been possible. All third-party libraries or products we redistribute are unmodified (unforked) copies.

Same for Plone. Daisy seems to be based on Cocoon. Plone is based on Zope.

Some of the main features of the document repository are:
* Storage and retrieval of documents.

Documents are one of the numerous object classes available in Plone. The basic object in Plone is… an object that is not fully extensible by itself unless it was designed to be so. Plone content types are more user-oriented than generic documents (they implement specialized behaviours such as security rules, workflows, displays, …). They will be made very extensible when the next versions of the “Archetypes” underlying layer is released (they include through-the-web schema management feature that allow web users to extend what any existing content type is).

* Documents can consists of multiple content parts and fields, document types define what parts and fields a document should have.

Plone’s perspective is different because of its object orientation. Another Zope product called Silva is more similar to Daisy’s document orientation.

Fields can be of different data types (string, date, decimal, boolean, …) and can have a list of values to choose from.

Same for Archetypes based content types in Plone.

Parts can contain arbitrary binary data, but the document type can limit the allowed mime types. So a document (or more correctly a part of a document) could contain XML, an image, a PDF document, … Part upload and download is handled in a streaming manner, so the size of parts is only limitted by the available space on your filesystem (and for uploading, a configurable upload limit).

I imagine that Daisy allows the upload and download of documents having any structure, with no constraint. In Plone, you are constrained by the object model of your content types. As said above this model can be extended at run time (schema management) but at the moment, the usual way to do is to define your model at design time and then comply with it at run time. At run time (even without schema management), you can still add custom metadata or upload additional attached files if your content type supports attached files.

* Versioning of the content parts and fields. Each version can have a state of ‘published’ or ‘draft’. The most recent version which has the state published is the ‘live’ version, ie the version that is displayed by default (depends on the behaviour of the frontend application of course).

The default behaviour of Plone does not include real versioning but document workflows. It means that a given content can be in state ‘draft’ or ‘published’ and go from one state to another according to a pre-defined workflow (with security conditions, event triggering and so). But a given object has only one version by default.
But there are additional Plone product that make Plone support versioning. These products are to be merged into Plone future distribution because versioning has been a long awaited feature. Note that, at the moment, you can have several versions of a document to support multi-language sites (one version per language).

* Documents can be marked as ‘retired’, which makes them appear as deleted, they won’t show up unless explicitely requested. Documents can also be deleted permanently.

Plone’s workflow mechanism is much more advanced. A default workflow includes a similar retired state. But the admin can define new workflows and modify the default one, always referring to the user role. Plone’s security model is quite advanced and is the underlying layer of every Plone functionality.

* The repository doesn’t care much what kind of data is stored in its parts, but if it is “HTML-as-well-formed-XML”, some additional features are provided:
o link-extraction is performed, which allows to search for referers of a document.
o a summary (first 300 characters) is extracted to display in search results
o (these features could potentially be supported for other formats also)

There is no such thing in Plone. Maybe in Silva ? Plone’s reference engine allows you to define associations between objects. These associations are indexed by Plone’s search engine (”catalog”) and can be searched.

* all documents are stored in one “big bag”, there are no directories.

Physically, the ZODB repository can have many forms (RDBMS, …). The default ZODB repository is a single flat file that can get quite big : Data.fs

Each document is identified by a unique ID (an ever-increasing sequence number starting at 1), and has a name (which does not need to be unique).

Each object has an ID but it is not globally unique at the moment. It is unfortunately stored in a hierarchical structure (Zope’s tree). Some Zope/Plone developpers wished “Placeless content” to be implemented. But Daisy must still be superior to Plone in that field.

Hierarchical structure is provided by the frontend by the possibility to create hierarchical navigation trees.

Zope’s tree is the most important structure for objects in a Plone site. It is too much important. You can still create navigation trees with shortcuts. But in fact, the usual solution in order to have maximum flexibility in navigation trees is to use the “Topic” content type. Topics are folder-like object that contain a dynamic list of links to objects matching the Topic’s pre-defined query. Topic are like persistent searches displayed as folders. As a an example a Topic may display the list of all the “Photo”-typed objects that are in “draft” state in a specific part (tree branch) of the site, etc.

* Documents can be combined in so-called “collections”. Collections are sets of the documents. One document can belong to multiple collections, in other words, collections can overlap.

Topics too ? I regret that Plone does easily not offer a default way to display a whole set of objects in just one page. As an example, I would have enjoyed to display a “book” of all the contents in my Plone site as if it were just one single object (so that I can print it…) But there are some Plone additional products (extensions) that support similar functionalities. I often use “Content Panels” to build a page by defining its global layout (columns and lines) and by filling it with “views” from exisiting Plone objects (especially Topics). Content Panels mixed with Topics allow a high flexibility in your site. But this flexibility has some limits too.

* possibility to take exclusive locks on documents for a limitted or unlimitted time. Checking for concurrent modifications (optimistic locking) happens automatically.

See versioning above.

* documents are automatically full-text indexed (Jakarta Lucene based). Currently supports plain text, XML, PDF (through PDFBox), MS-Word, Excel and Powerpoint (through Jakarta POI), and OpenOffice Writer.

Same for Plone except that Plone’s search engine is not Lucene and I don’t know if Plone can read OpenOffice Writer documents. Note that you will require additional modules depending on your platform in order to read Microsoft files.

* repository data is stored in a relation database. Our main development happens on MySQL/InnoDB, but the provisions are there to add support for new databases, for example PostgreSQL support is now included.

Everything is in the ZODB. By default stored as a single file. But can also be stored in a relational database (but this is usually useless). You can also transparently mix several repositories in a same Plone instance. Furthermore, instead of having Plone directly writing in the ZODB’s file, you can configure Plone so that it goes through a ZEO client-server setup so that several Plone instances can share a common database (load balancing). Even better, there is a commercial product, ZRS, that allows you to transparently replicate ZODBs so that several Plone instances setup with ZEO can use several redundant ZODBs (no single point of failure).

The part content is stored in normal files on the file system (to offload the database). The usage of these familiar, open technologies, combined with the fact that the daisywiki frontend stores plain HTML, makes that your valuable content is easily accessible with minimal “vendor” lock-in.

Everything’s in the ZODB. This can be seen as a lock-in. But it is not really because 1/ the product is open source and you can script a full export with Python with minimal effort, 2/ there are default WebDAV + FTP services that can be combined with Plone’s Marshall extension (soon to be included in Plone’s default distribution) that allows you to output your content from your Plone site. Even better, you can also upload your structured semantic content with Marshall plus additional hacks as I mentioned somewhere else.

* a high-level, sql-like query language provides flexible querying without knowing the details of the underlying SQL database schema. The query language also allows to combine full-text (Lucene) and metadata (SQL) searches. Search results are filtered to only contain documents the user is allowed to access (see also access control). The content of parts (if HTML-as-well-formed-XML) can also be selected as part of a query, which is useful to retrieve eg the content of an “abstract” part of a set of documents.

No such thing in Plone as far as I know. You may have to Pythonize my friend… Except that Plone’s tree gives an URL to every object so that you can access any part of the site. But not with a granularity similar to Daisy’s supposed one. See silva for more document-orientation.

* Accesscontrol: instead of attaching an ACL to each individual document, there is a global ACL which allows to specify the access rules for sets of documents by selecting those documents based on expressions. This allows for example to define access control rules for all documents of a certain type, or for all documents in a certain collection.

Access control is based on Plone’s tree, with inheritance (similar to Windows security model in some way). I suppose Plone’s access control is more sophisticated and maintainable than Daisy’s one but it should require more investigation to explain why.

* The full functionality of the repository is available via an HTTP+XML protocol, thus providing language and platform independent access. The documentation of the HTTP interface includes examples on how the repository can be updated using command-line tools like wget and curl.

Unfortunately, Plone is not ReST enough at the moment. But there is some hope the situation will change with Zope 3 (Zope’s next major release that is coming soon). Note that Zope (so Plone) supports HTTP+XML/RPC as a generic web service protocol. But this is nothing near real ReSTful web services…

* A high-level, easy to use Java API, available both as an “in-JVM” implementation for embedded scenarios or services running in the daisy server VM, as well as an implementation that communicates transparently using the HTTP+XML protocol.

Say Python and XML/RPC here.

* For various repository events, such as document creation and update, events are broadcasted via JMS (currently we include OpenJMS). The content of the events are XML messages. Internally, this is used for updating the full-text index, notification-mail sending and clearing of remote caches. Logging all JMS events gives a full audit log of all updates that happened to the repository.

No such mechanism as far as I know. But Plone of course offers fully detailed audit logs of any of its events.

* Repository extensions can provide additional services, included are:
o a notification email sender (which also includes the management of the subscriptions), allowing subscribing to individual documents, collections of documents or all documents.

No such generic feature by default in Plone. You can add scripts to send notification in any workflow transition. But you need to write one or two lines of Python. And the management of subscriptions is not implemented by default. But folder-like object support RSS syndication so that you can agregate Plone’s new objects in your favorite news aggregator;

o a navigation tree management component and a publisher component, which plays hand-in-hand with our frontend (see further on)

I’ll see further on… :)

* A JMX console allows some monitoring and maintenance operations, such as optimization or rebuilding of the fulltext index, monitoring memory usage, document cache size, or database connection pool status.

You have several places to look at for this monitoring within Zope/Plone (no centralized monitoring). An additional Plone product helps in centralizing maintenance operations. Still some ground for progress here.

The “Daisywiki” frontend
The frontend is called the “Daisywiki” because, just like wikis, it provides a mixed browsing/editing environment with a low entry barrier. However, it also differs hugely from the original wikis, in that it uses wysiwyg editing, has a powerful navigation component, and inherits all the features of the underlying daisy repository such as different document types and powerful querying.

Well, then we can just say the same for Plone and rename its skins the Plonewiki frontend… Supports Wysiwyg editing too, with customizable navigation tree, etc.

* wysiwyg HTML editing
o supports recent Internet Explorer and Mozilla/Firefox (gecko) browsers, with fallback to a textarea on other browsers. The editor is customized version of HTMLArea (through plugins, not a fork).

Same for Plone (except it is not an extension of HTMLArea but of a similar product).

o We don’t allow for arbitrary HTML, but limit it to a small, structural subset of HTML, so that it’s future-safe, output medium independent, secure and easily transformable. It is possible to have special paragraph types such as ‘note’ or ‘warning’. The stored HTML is always well-formed XML, and nicely layed-out. Thanks to a powerful (server-side) cleanup engine, the stored HTML is exactly the same whether edited with IE or Mozilla, allowing to do source-based diffs.

No such validity control within Plone. In fact, the structure of a Plone document is always valid because it is managed by Plone according to a specific object model. But a given object may contain an HTML part (a document’s body as an example) that may not be valid. If your documents are to have a recurrent inner structure, then you are invited to make this structure an extension of an object class so that is no more handled as a document structure. See what I mean ?

o insertion of images by browsing the repository or upload of new images (images are also stored as documents in the repository, so can also be versioned, have metadata, access control, etc)

Same with Plone except for versioning. Note that Plone’s Photo content type support automatic server-side redimensioning of images.

o easy insertion document links by searching for a document

Sometimes yes, sometimes no. It depends on the type of link you are creating.

o a heartbeat keeps the session alive while editing

I don’t know how it works here.

o an exlusive lock is automatically taken on the document, with an expire time of 15 minutes, and the lock is automatically refreshed by the heartbeat

I never tried the Plone extension for versioning so I can’t say. I know that you can use the WebDAV interface to edit a Plone object with your favorite text processing package if you want. And I suppose this interface properly manages this kind of issues. But I never tried.

o editing screens are built dynamically for the document type of the document being edited.

Of course.

* Version overview page, from which the state of versions can be changed (between published and draft), and diffs can be requested. * Nice version diffs, including highlighting of actual changes in changed lines (ignoring re-wrapping).

You can easily move any object in its associated workflow (from one state to another, through transitions). But no versioning. Note that you can use Plone’s wiki extension and this extension supports supports diffs and some versioning features. But this is not available for any Plone content type.

* Support for includes, i.e. the inclusion of one document in the other (includes are handled recursively).

No.

* Support for embedding queries in pages.

You can use Topics (persistent queries). You can embed them in Content Panels.

* A hierarchical navigation tree manager. As many navigation trees as you want can be created.

One and only one navigation tree by default. But Topics can be nested. So you can have one main navigation tree plus one or more alternatives with Topics (but these alternatives are limited for some reasons.).

Navigation trees are defined as XML and stored in the repository as documents, thus access control (for authoring them, read access is public), versioning etc applies. One navigation tree can import another one. The nodes in the navigation tree can be listed explicitely, but also dynamically inserted using queries. When a navigation tree is generated, the nodes are filtered according to the access control rules for the requesting user. Navigation trees can be requested in “full” or “contextualized”, this last one meaning that only the nodes going to a certain document are expanded. The navigtion tree manager produces XML, the visual rendering is up to XSL stylesheets.

This is nice. Plone can not do that easily. But what Plone can do is still done with respect to its security model and access control, of course.

* A navigation tree editor widget allows easy editing of the navigation trees without knowledge of XML. The navigation tree editor works entirely client-side (Mozilla/Firefox and Internet Explorer), without annoying server-side roundtrips to move nodes around, and full undo support.

Yummy.

* Powerful document-publishing engine, supporting:
o processing of includes (works recursive, with detection of recursive includes)
o processing of embedded queries
o document type specific styling (XSLT-based), also works nicely combined with includes, i.e. each included document will be styled with its own stylesheet depending on its document type.

OK

* PDF publishing (using Apache FOP), with all the same features as the HTML publishing, thus also document type specific styling.

Plone document-like content type offer PDF views too.

* search pages:
o fulltext search
o searching using Daisy’s query language
o display of referers (”incoming links”)

Fulltext search is available. No query language for the user. Display of refers is only available for content type that are either wiki pages or have been given the ability to include references from other objects.

* Multiple-site support, allows to have multiple perspectives on top of the same daisy repository. Each site can have a different navigation tree, and is associated with a default collection. Newly created documents are automatically added to this default collection, and searches are limited to this default collection (unless requested otherwise).

It might be possible with Plone but I am not sure when this would be useful.

* XSLT-based skinning, with resuable ‘common’ stylesheets (in most cases you’ll only need to adjust one ‘layout’ xslt, unless you want to customise heavily). Skins are configurable on a per-site basis.

Plone’s skins are using the Zope Page Templates technology. This is a very nice and simple HTML templating technology. Plone’s skins make an extensive use of CSS and in fact most of the layout and look-and-feel of a site is now in CSS objects. These skins are managed as objects, with inheritance, overriding of skins and other sophisticated mechanism to configure them.

* User self-registration (with the possibility to configure which roles are assigned to users after self-registration) and password reminder.

Same is available from Plone.

* Comments can be added to documents.

Available too.

* Internationalization: the whole front-end is localizable through resource bundles.

Idem.

* Management pages for managing:
o the repository schema (the document types)
o the users
o the collections
o access control

Idem.

* The frontend currently doesn’t perform any caching, all pages are published dynamically, since this also depends on the access rights of the current user. For publishing of high-trafic, public (ie all public access as the same user), read-only sites, it is probably best to develop a custom publishing application.

Zope includes caching mechanisms that take care of access rights. For very high-trafic public sites, a Squid frontend is usually recommended.

* Built on top of Apache Cocoon (an XML-oriented web publishing and application framework), using Cocoon Forms, Apples (for stateful flow scenarios), and the repository client API.

By default, Zope uses its own embedded web server. But the usual setup for production-grade sites is to put an Apache reverse-proxy in front of it.

My conclusion : Daisy looks like a nice product when you have a very document-oriented project, with complex documents with structures varying much from documents to documents ; its equivalent in Zope’s world would be Silva. But Plone is much more appropriate for everyday CMS sites. Its object-orientation offers both a great flexibility for the developer and more ease of use for Joe-six-pack webmaster. Plone still lacks some important technical features for its future, namely ReSTful web service interfaces, plus placeless content paradigm. Versioning is expected soon.

This article was written in just one raw, late at night and with no re-reading reviewed once thanks to Gouri. It may be wrong or badly lacking information on some points. So your comments are much welcome !

In my opinion, they should carry on the current trend on emphasizing corporate social responsability. In order to do so, they should both embrace innovative reporting standards and methodologies and support these methodologies by implementing them with “semantic web”-like technologies. In such a future, it would mean that financial analyst (and eventually stakeholders) should be able to browse through specialized web sites which would aggregate meaningful data published in these corporate reports. In such specialized web sites, investors should be able to compare comparable data, marks and ratings regarding their favorite corporations. They should be given functionalities like the one you find in multidimensional analysis tools (business intelligence), even if they are as simplified as in interactive purchase guides [via Fred]. In such a future, I would be able to subscribe to such a web service, give my preferences and filters in financial, social and environmental terms. This service would give me a snapshot of how the selected corporations compare one to each other regarding my preferences and filters. Moreover, I would receive as an RSS feed an alert whenever a new report is published or when some thresholds in performance are reached by the corporations I monitor.

Some technological issues still stand in the way of such future. They are fading away. But a huge amount of methodological and political issues stand there also… What if such technologies come to maturity ? Would they push corporations, rating agencies, analysts and stakeholders to change their minds and go in the right direction ?

1. Choose any existing OWL ontology
2. With Protege equipped with its OWL plugin, create a new project from your OWL file.
3. Still within Protege, with the help of its UML plugin, convert your OWL-Protege project into a UML classes project. You get an XMI file.
4. Load this XMI file into an UML project with Poseidon. Save this project under the .zuml Poseidon format.
5. From poseidon, export your classes a new xmi file. It will be Plone-friendly.
6. With a text editor, delete some accentuated characters that Poseidon might have added to your file (for example, the Frenchy Poseidon adds a badly accentuated “Modele sans titre” attribute into your XMI) because the next step won’t appreciate them
7. python Archgenxml.py -o YourProduct yourprojectfile.xmi turns your XMI file into a valid Plone product. Requires Plone and Archetypes (see doc) latest stable version plus ArchgenXML head from the subversion repository.
8. Launch your Plone instance and install YourProduct as a new product from your Plone control panel. Enjoy YourProduct !
9. eventually populate it with an appropriate marshaller.

Now you are not far from using Plone as a semantic aggregator.

• “The popularity of most Free and Open Source CMS tools is in an upward trend.“
• Bulletin boards like phpBB is the most popular category, maybe the most mature and phpBB is the strong leader in this category
• In the CMS category, Mambo, Xoops, Drupal and Plone are direct competitors ; Mambo is ahead in terms of popularity, Plone is behind its PHP competitors which certainly benefit from the popularity of PHP compared to Python; PHP-Nuke and PostNuke are quickly loosing some ground.
• Wordpress is the most dynamic open source blog engine in terms of growth of popularity ; its community is exploding

My conclusion :

• if you want an open source bulletin board/community forum, then choose phpBB with no hesitation
• if you want a real content management system and are not religiously opposed to Python, then choose Plone, else stick with PHP and go Mambo (or Xoops ?)
• if you want an open source blog engine, then enjoy Wordpress

If feel like producing this kind of statistical analysis about the dynamics of open source communities is extremely valuable for organization and people considering several open source options (cf. the activity percentile indicated on sourceforge projets as an example). I would tend to say that the strength of an open source community, measured in term of growth and size, is the one most important criteria to rely on when choosing an open source product.

Nowadays, the (real) stock market relies strongly on rating agencies. There must be a room (and thus a business opportunity) for an open source rating agency that would produce strong evidences about the relative strength of project communities.

What do you think ?

You may be used with HTML templates for producing HTML pages. An HTML template plus structured data can be transformed into a set of HTML pages with the help of a proper templating engine. One famous technology for HTML templating is called Zope Page Templates (because this kind of templates is used within the Zope application server). ZPTs use a special set of additional HTML tags and attributes referred to by the “tal:” namespace. One advantage of ZPT (over competing technologies) is that ZPT are nicely rendered in WYSIWYG HTML editors. Thus web designers produce HTML mockups of the screens to be generated by the application. Web developpers insert tal: attributes into these HTML mockups so that the templating engine will know which parts of the HTML template have to be replaced by which pieces of data (usually pumped from a database). As an example, web designers will say <title>Camcorder XYZ</title> then web developpers will modify this into <title tal:content=”camcorder_name”>Camcorder XYZ</title> and the templating engine will further produce a <title>Camcorder Canon MV6iMC</title> when it processes the “MV6iMC” record in your database (it replaces the content of the title element with the value of the camcorder_name variable as it is retrieved from the current database record). This technology is used to merge structured data with HTML templates in order to produce Web pages.

I took inspiration from this technology to design parsing templates. The idea here is to reverse the use of HTML templates. In the parsing context, HTML templates are still produced by web developpers but the templating engine is replaced by a parsing engine (known as web_parser.py, see below for the code of this engine). This engine takes HTML pages (the ones you previously crawled and retrieved) plus ZPT-like HTML templates as input. It then outputs structured data. First your crawler saved <title>Camcorder Canon MV6iMC</title>. Then you wrote <title tal:content=”camcorder_name”>Camcorder XYZ</title> into a template file. Eventually the engine will output camcorder_name = “Camcorder Canon MV6iMC”.

In order to trigger the engine, you just have to write a small launch script that defines several setup variables such as :

• the URL of your template file,
• the list of URLs of the HTML files to be parsed,
• whether you would like or not to pre-process these files with an HTML tidying library (this is useful when the engine complains about badly formed HTML),
• an arbitrary keyword defining the domain of your parsing operation (may be the name of the web site your HTML files come from),
• the charset these HTML files are made with (no automatic detection at the moment, sorry…)
• the output format (csv-like file or semantic web document)
• an optional separator character or string if ever you chose the csv-like output format

The easiest way to go is to copy and modify my example launch script (parser_dvspot.py) included in the ZIP distribution of this web_parser.

Let’s summarize the main steps to go through :

1. install utidylib into your python installation
2. copy and save my modified version of BeautifulSoup into your python libraries directory (usually …/Lib/site-packages)
3. copy and save my engine (web_parser.py) into your local directory or into you python libraries directory
4. choose a set of HTML files on your hard drive or directly on a web site,
5. save one of these files as your template,
6. edit this template file and insert the required pseudotal attributes (see below for pseudotal instructions, and see the example dvspot template template_dvspot.zpt),
7. copy and edit my example launch script so that you define the proper setup variables in it (the example parser_dvspot.py contains more detailed instructions than above), save it as my_script.py
8. launch your script with a python my_script.py > output_file.cowl (or python my_script.py > output_file.cowl)
9. enjoy yourself and your fresh output_file.owl or output_file.csv (import it within Excel)
10. give me some feedback about your reverse-templating experience (preferably as a comment on this blog)

This is just my first attempt at building such an engine and I don’t want to make confusion between real (and mature) tal attributes and my pseudo-tal instructions. So I adopted pseudotal as my main namespace. In some future, when the specification of these reverse-templating instructions are somewhat more stabilized (and if ever the “tal” guys agree), I might adopt tal as the namespace. Please also note that the engine is somewhat badly written : the code and internal is rather clumsy. There is much room for future improvement and refactoring.

The current version of this reverse-templating engine now supports the following template attributes/instructions (see source code for further updates and documentation) :

• pseudotal:content gives the name of the variable that will contain the content of the current HTML element
• pseudotal:replace gives the name of the variable that will contain the entire current HTML element
• (NOT SUPPORTED YET) pseudotal:attrs gives the name of the variable that will contain the (specified?) attribute(s ?) of the current HTML element
• pseudotal:condition is a list of arguments ; gives the condition(s) that has(ve) to be verified so that the parser is sure that current HTML element is the one looked after. This condition is constructed as a list after BeautifulSoup fetch arguments : a python dictionary giving detailed conditions on the HTML attributes of the current HTML element, some content to be found in the current HTML element, the scope of research for the current HTML element (recursive search or not)
• pseudotal:from_anchor gives the name of the pseudotal:anchor that is used in order to build the relative path that leads to the current HTML element ; when no from_anchor is specified, the path used to position the current HTML element is calculted from the root of the HTML file
• pseudotal:anchor specifies a name for the current HTML element ; this element can be used by a pseudotal:from_anchor tag as the starting point for building the path to the element specified by pseudotal:from_anchor ; usually used in conjunction with a pseudotal:condition ; the default anchor is the root of the HTML file.
• pseudotal:option describes some optional behavior of the HTML parser ; is a list of constants ; contains NOTMANDATORY if the parser should not raise an error when the current element is not found (it does as default) ; contains FULL_CONTENT when data looked after is the whole content of the current HTML element (default is the last part of the content of the current HTML element, i.e. either the last HTML tags or the last string included in the current element)
• pseudotal:is_id_part a special ‘id’ variable is automatically built for every parsed resource ; this id variable is made of several parts that are concatenated ; this pseudotal:is_id_part gives the index the current variable will be used at for building the id of the current resource ; usually used in conjunction with pseudotal:content, pseudotal:replace or pseudotal:attrs
• (NOT SUPPORTED YET) pseudotal:repeat specifies the scope of the HTML tree that describes ONE resource (useful when several resources are described in one given HTML file such as in a list of items) ; the value of this tag gives the name of a class that will instantiate the parsed resource scope plus the name of a list containing all the parsed resource

The current version of the engine can output structured data either as a CSV-like output (tab-delimited for example) or as an RDF/OWL document (of Semantic-Web fame). Both formats can easily be imported and further processed with Excel. The RDF/OWL format gives you the ability to process it with all the powerful tools that are emerging along the Semantic Web effort. If you feel adventurous, you may thus import your RDF/OWL file into Stanford’s Protege semantic modeling tool (or into Eclipse with its SWEDE plugin) and further process your data with the help of a SWRL rules-based inference engine. The future Semantic Web Rules Language will help at further processing this output so that you can powerfully compare RDF data coming from distinct sources (web sites). In order to be more productive in terms of fancy buzz-words, let’s say that this reverse-templating technology is some sort of a web semantizer. It produces semantically-rich data out of flat web pages.

The current version of the engine makes an extensive use of BeautifulSoup. Maybe it should have been based on a more XMLish approach instead (using XML pathes ?). B