wikyoto knowledge editor: the collaborative web environment to

WIKYOTO KNOWLEDGE EDITOR: THE COLLABORATIVE WEB ENVIRONMENT TO MANAGE KYOTO MULTILINGUAL KNOWLEDGE BASE ANDREA MARCHETTI, SALVATORE MINUTOLI, FRANCESCO RONZANO and MAURIZIO TESCONI Institute for Informatics and Telematics, National Research Council CNR Via G. Moruzzi, 1 - Pisa, Italy E-mail: {andrea.machetti,salvatore.minutoli,francesco.ronzano,maurizio.tesconi}@iit.cnr.it Kyoto is a knowledge-driven system for fact mining from a multilingual collection of information sources concerning a specific domain of interest. Facts are mined from relevant documents that are linguistically and semantically annotated exploiting a Multilingual Knowledge Base, made of several language-specific WordNets all referred to a common Central Ontology. In this paper we introduce a core component of KYOTO, the Wikyoto Knoweldge Editor: it is the collaborative Web environment where the multilingual and multicultural community of KYOTO users interacts to maintain and extend, in respect to their particular domain of interest, the background knowledge of KYOTO, constituting the Multilingual Knowledge Base. After an overview of the most relevant examples of collaborative environments to manage knowledge resources, we briefly introduce KYOTO architecture to provide the global context to describe the Wikyoto Knowledge Editor. Thus we focus our attention on the description of the Wikyoto Knowledge Editor, introducing its purpose inside KYOTO, its architecture and its Web-based user interface. By mean of an example, we explain how KYOTO Multilingual Knowledge Base can be browsed and enriched by the Wikyoto Knowledge Editor both thanks to the suggestions provided by the terminology automatically mined from documents in KYOTO and by accessing other external Web resources, like DBpedia. We consider the first working prototype of the Wikyoto Knowledge Editor, implementing a core set of relevant features. In conclusion, we expose our future works summarizing all the features that are planned to be supported in the upcoming versions of the Wikyoto Knolwedge Editor.

1.

Introduction: collaborative environments to manage knowledge resources

During the last few years, different kinds of collaborative environments have been developed in order to group together and support the interactions among all the actors involved in the process of creation and gradual refinement of knowledge resources, like ontologies or, in general, any semantic and linguistic network. To manage this kind of contents the wiki paradigm has been largely adopted, often in conjunction with the exploitation of Web-based interactions. Moreover, as a consequence of the great diffusion experimented by Semantic Web principles and standards, ontological resources have gained a central role in the Web as the global mean to provide shared conceptualizations to easily exchange and integrate knowledge between different communities of users. Knowledge resources are more and more exploited as the background reference for knowledge-intensive tasks like text mining, semantic grounding of data and information extraction; thus they need to be well structured, often tailored to a particular domain and constantly enriched and kept up to date so as to reflect the changes in the knowledge they describe. Knowledge resources are usually shared among communities of users, often distributed and heterogeneous, that need to reach consensus: users are thus important actors also in their management process. They usually range from experts in knowledge

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2 representation to people with a lot of expertise in the knowledge domain being described but with no experience on the best way to formalize and express it: both these categories of users are essential and should be involved so as to correctly manage and maintain knowledge resources. In order to deal with such a scenario, distinct solutions have been proposed, thus developing methodologies and tools for different kinds of knowledge resources in a collaborative way; these tools can be grouped into two great categories: o Wiki tools to semantically structure information: easily exploitable by people with little or no experience in knowledge-modeling, they help users to easily point out structured knowledge usually from unstructured texts, by identifying appropriate semantic patterns in a user-friendly way. As a consequence, the formalized knowledge can be exploited to increase the support for a better information search and management. In order to be accessed by distributed user communities, these tools are usually provided with a Web interface. Three relevant examples are Semantic MediaWiki, OntoWiki and IkeWiki. o Complex knowledge modeling environments: they are mainly exploited by experts who fully model knowledge according to a specific and well-known representational schema. In order to realize all these features they are usually implemented as stand-alone desktop applications. Three important examples are Protégé, the NeOn Toolkit and Ontoverse. In what follows we give a brief overview of the just mentioned examples of knowledge editing environments of both categories. Semantic MediaWikia (Krötzsch et al. 2006) is a semantic extension of MediaWikib, the wiki engine supporting the most important wiki projects like Wikipedia: it aims at extending Wikipedia contents with more structure and semantics so as to increase their consistency, their reuse and to facilitate their access exploiting semantic search patterns. It allows users to easily annotate page contents, making explicit the properties referred to link one page to other ones or defining the Category (or class) the considered page belongs to. Hierarchies of classes can be easily defined as well as new properties to link pages. RDF/OWL exports of structured information can be automatically generated. OntoWikic (Auer et al. 2006) is a tool for collaborative knowledge editing. It is a Webbased ontology editor and a collaborative knowledge acquisition tool: it provides a graphic user interface for an easy and visual editing of RDF knowledge bases. OntoWiki allows defining instances with respect to ontology classes and properties, visualizing particular kinds of data through custom views, avoiding repetition of information and allowing also non-expert users to easily understand knowledge organization. IkeWikid (Schaffert 2006), the last considered example of Wiki tools to semantically structure information, is a semantic wiki that allows users to describe pages and links between pages with semantic annotations, in a way compatible with MediaWiki. IkeWiki implements Semantic Web standards like RDF and OWL and supports different levels of knowledge formalization and different users’ expertise.

a http://semantic-mediawiki.org/wiki/Semantic_MediaWiki b http://www.mediawiki.org/ c http://ontowiki.net/Projects/OntoWiki d http: http://ikewiki.salzburgresearch.at/

3 The KiWie (Knowledge In a Wiki) Project, co-founded by the European Commission, starting also from the background provided by the IkeWiki experience, aims at analyzing the most adequate way to define and make semantic wikis usable by huge communities of users, in a user-centric environment. Moving to examples of tools belonging to the category of Complex knowledge modeling environments, Protégéf (Tudorache and Noy 2007) represents a relevant one. It is an open-source extensible Java framework, mainly intended for knowledge modeling experts, useful to edit ontologies that can be expressed also in RDF(S) and OWL. It is one of the most widely spread ontology editing environments, adopted by a huge community of users. It is based on a client-server architecture. Recently Web Protégé (Tudorache et al. 2008), a Web Interface for Protégé has been developed so as to provide basic ontology editing features through a Web browser and the definition of workflows for collaborative ontology development (Abraham et al. 2008). Also the NeOn Toolkitg, developed in the context of the NeOn (Networked Ontologies) Projecth, co-founded by the European Commission, is a rich ontology editing environment. It allows editing F-logic, RDF(S) and OWL ontologies, by mean of different visualization facilities, supporting also the definition of rules. Built on the top of Eclipse a widely exploited Java-based development tool, it is easily extensible exploiting a plug-in mechanism and currently a large number of plug-ins has been developed; they provide support to collaborative Web-based ontology editing as well as to other important tasks like ontology-related argumentation. Ontoversei (Bai et al. 2007), developed within the promotional focus of the German Federal Ministry of Education and Research on eScience and knowledge management, allows different actors to concurrently edit an ontology with a great focus on collaboration aspects and group awareness: users can discuss over ontology changes and constantly monitor their concurrent modifications. Ontoverse interface is Web-based, but for ontology editing and alignment tasks it relies upon the Java applet technology. Besides the six examples of knowledge editing tools just described, AceWikij (Khun 2008) represents another one that deserve to be mentioned since it exploits a different approach to let users easily edit and refine ontologies. It relies upon the Attempto Controlled English (ACE), a controlled language similar to the natural language, so as to let users modify ontologies avoiding the use of complex constructs difficult to understand especially for non-expert ones. All the controlled language knowledge descriptions are validated and converted into ontological statements. All the described examples of collaborative tools for knowledge management underline how many relevant issues need to be faced when we have to provide users with a useful environment to browse and edit knowledge resources: besides the ease of interaction for the different kinds of users with different levels of expertise, we have also to consider the ease of accessing such a kind of environments, sometimes provided exploiting a clientserver architecture and a browser-based Web interface. Argumentation facilities are e http://www.kiwi-project.eu/ f http://protege.stanford.edu/ g http://neon-toolkit.org/ h http://www.neon-project.org/ i http://www.ontoverse.org/ j http://attempto.i_.uzh.ch/acewiki/

4 needed as well as concurrency controls and consistency checks over the edited knowledge. User-specific editing permissions and versioning support are two other relevant features of these Wiki Web-based knowledge-management environments that have been partially addressed also by the analyzed tools. On the basis of all these considerations, examples and analysis done, the rest of this paper is focused on the presentation of our Wiki Web-based knowledge management environment, the Wikyoto Knowledge Editor: it allows KYOTO users to explore and collaboratively enrich and refine the set of knowledge resources exploited in KYOTO. KYOTO is a knowledge-driven environment where groups of users in a particular domain of interest can collaboratively model knowledge by mining textual documents, finding and sharing facts across different languages and cultures: it is currently under development in the context of the Asian-European homonym Project. All these tasks are carried out by exploiting the knowledge cumulated in the KYOTO Multilingual Knowledge Base. Thanks to the Wikyoto Knowledge Editor, the Knowledge Base is collaboratively modeled and enriched via a browser-based Web interface, by involving users with different levels of expertise, constituting a particular community of interest; they can integrate and map distinct terminological resources, structuring KYOTO knowledge spanning over seven languages. Each modification done to the resources of the KYOTO Multilingual Knowledge Base immediately affects the text mining and semantic processing capabilities and effectiveness of the whole KYOTO system that relies upon it. In Section 2, we briefly introduce the global architecture of the KYOTO system so as to provide a frame of reference to contextualize the Wikyoto Knowledge Editor. It is out of the scope of this paper to provide a detailed description of all the components of KYOTO: they are only shortly introduced as far as concern the comprehension of the Wikyoto Knowledge Editor. In Section 3 we describe the features of the Wikyoto Knowledge Editor with particular focus on the architecture of the first implemented prototype, underlying the possibility to exploit the terminology mined from KYOTO parsed documents as well as the access external resources so as to enrich the Multilingual Knowledge Base. In Section 4 we expose our conclusion and future works. 2.

The KYOTO System and the Wikyoto Knowledge Editor

KYOTO architecture, involving different modules and data repositories, is schematized in Figure 1, where the attention is focused on the main interactions and flows of information among all the components of the system and between the system and its users. In the rest of this Section we provide a brief overview of how the whole system works. This description doesn’t claim to be an exhaustive one since the main focus of this Section is to introduce the general context where the Wikyoto Knowledge Editor comes into play: to get further information about KYOTO, as well as more technical details about the different parts of the system, you can access the KYOTO Project Official Web Site, http://www.kyoto-project.eu/. In KYOTO, system users are classified by role, ranging from the End Users that mainly access the system to perform searches, to other kinds of users directly involved in relevant knowledge management tasks: the Concept Users and the Fact Users. In particular, Concept Users are the ones who directly interact with the Wikyoto Knowledge Editor.

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Fig. 1. Global architecture of the KYOTO system: knowledge processing activities.

All the documents of interest for KYOTO users (whatever is their format: HTML pages, MSWord or PDF, expressed in all the languages involved in the Project) are collected and indexed in the Original Document Base: End Users can perform keyword-based searches on their contents. All those documents are linguistically and semantically annotated thanks to languagespecific Linguistic Processors. Semantic annotation is performed by accessing the language-specific knowledge retrieved from the Multilingual Knowledge Base. The annotation results are represented, in a language-independent way, thanks to the KYOTO Annotation Format (KAF) and stored in the Syntactic & Semantic KAF Base. Semantic annotation of documents can be repeated over time since the background knowledge exploited to perform this task, contained in the Multilingual Knowledge Base, is continuously updated by KYOTO Concept Users, by mean of the Wikyoto Knolwedge Editor. The Multilingual Knowledge Base (see Figure 2) represents the semantic backbone for all the information mining and extraction tasks of the KYOTO system: it includes languagespecific words and expressions, encoded in different WordNets, one for each language, all mapped to a shared language-neutral ontology, the KYOTO Central Ontology, so as to unify the particular and cultural-specific lexical patterns of each language. WordNets are lexical databases, built on the basis of the structure of the English WordNet, developed at Princeton Universityk. Currently KYOTO includes the WordNets of seven European and Asian languages: English, Dutch, Italian, Spanish, Basque, Simplified Mandarin Chinese and Japanese. Those lexical resources are represented in a custom data format: KYOTO-LMF, derived from the Lexical Markup Framework (LMF, ISO/TC37). The KYOTO-1-Central-Ontology, the first version of the unifying KYOTO Central Ontology, has been developed: it is based on a modified version of DOLCE-Lite-Plusl k http://wordnet.princeton.edu/ l http://wiki.loa-cnr.it/index.php/LoaWiki:DOLCE-Lite-Plus

6 and has been manually extended with middle level concepts, including Base Concepts that have been automatically derived from WordNet 3.0.

Fig.2 . Structure of the KYOTO Multilingual Knowledge Base

Both WordNets and the Central Ontology are divided into a fixed generic part and a domain specific extension. Thanks to the Wikyoto Knowledge Editor, WordNets and Ontology Domain extensions, that usually encode knowledge related to a specific domain of interest, can be created, maintained and enriched by KYOTO Concept Users, both domain experts and knowledge engineers, also by exploiting the suggestions of new terms provided by the KYOTO terminological collection, contained in the Term Base; all these issues will be better detailed in the following Section. All KYOTO annotated documents collected in the Syntactic & Semantic KAF Base are processed by the Fact Extractor, called also Knowledge Yielding Robot or Kybot, storing and indexing the gathered knowledge in the Fact Base. Fact Users can define, by mean of the Wikyoto Kybot Editor, the so called Kybot Profiles: they are language-independent conceptual patterns, relevant to the considered domain, that are associated to specific linguistic expressions in each language and are exploited to derive one or more facts from parsed documents. End Users can perform semantic searches in the knowledge collected in the Fact Base, on the basis of natural language queries and retrieving knowledge as well as relevant document excerpts. 3.

Wikyoto Knowledge Editor: the wiki for KYOTO Knowledge Base

The Wikyoto Knowledge Editor represents the collaborative environment where KYOTO Concept Users, both domain experts and knowledge engineers, can maintain the Multilingual Knowledge Base, creating and refining domain extension of the WordNets of a particular language and mapping these extensions to the KYOTO Central Ontology: the richer the Domain extensions of the WordNets and the Central Ontology, the deeper and more effective KYOTO semantic analysis of data can be. The collection of terms, hierarchically organized, extracted by the Tybot mining the documents processed by the KYOTO system, collected in the Term Base (see Figure 1), represents the fundamental terminological resource available to enrich the WordNets.

7 In this Section we describe the first working prototype of the Wikyoto Knowledge Editor: it is part of the KYOTO-I system, the first version of KYOTO that has been realized after the first year of Project. The Wikyoto Knowledge Editor is mainly an explorative prototype, but it is useful to show many relevant distinguishing core features of the wiki way to manage knowledge resources adopted in KYOTO. A new revised version of the Wikyoto Knowledge Editor, set up integrating a greater set of external knowledge resources, implementing full ontology editing capabilities as well as considering all the feedbacks coming from the usage of the considered prototype, will be released by the end of Summer 2009. 3.1. The overall architecture In order to make KYOTO users easily access the Knowledge Editor, it has been realized as a Web application exploitable through a common Web browser, relying upon universally adopted Web technologies and standards like (X)HTML, CSS and Javascript. To properly work, the Knowledge Editor needs to heavily interact with two resources belonging to the KYOTO system (see Figure 3): the Multilingual Knowledge Base and the Term Base. The Multilingual Knowledge Base is constituted by the generic and domain parts of the WordNets and the KYOTO Central Ontology, both stored in and managed by the DebVisDic Server. It is a storage system for semantic resources, conceived as a reimplementation of VisDic, a tool for editing WordNet semantic networks: it has been exploited to develop various types of dictionaries, i.e. monolingual, translational, thesauri and multilingually linked WordNet-like databases as well as during the Balkanet Projectm.

Fig.3 . Wikyoto Knowledge Editor architecture and interactions

The Term Base collects all the terms extracted by the Tybots parsing KAF annotated documents. Terms along with all the related information are stored in a properly structured relational database.

m http://www.uvt.nl/infolab/prj/balkanet/

8 Both the Multilingual Knowledge Base and the Term Base have been provided with a Web Application Programming Interface (API), properly structured to support REST API calls. Thus part of the processing logic of the Knowledge Editor has been implemented as client-side Javascript code interacting with the just mentioned APIs as well as with other external resources thanks to AJAX API calls as we can see in Figure 3. The Ext.js Javascript library has been adopted as the main programming facility so as to realize a highly interactive Web Interface as well as to easily manage the different data exchanges characterizing the Knowledge Editor. 3.2. The Web Interface Concept Users, by accessing their Web browser, once authenticated to the KYOTO system and after having chosen the language to consider so as to browse and enrich the corresponding WordNet, can access the Wikyoto Knowledge Editor Web interface. The global organization of this interface is shown in Figure 4. It is mainly divided into two parts: on the right side there is the WordNet Browser and Editor and on the left side the Term Browser and Editor. The WordNet Browser and Editor allows to browse a WordNet of a particular language, extending it by encoding new lexical information relevant to the domain of interest. The fundamental structure of WordNet is the synset, representing a sense and mainly characterized by a brief natural language description, called gloss, a part of speech and one or more words, called lemmas, used to refer to it: they all constitute synonyms in the WordNet of the particular language considered. Each synset of WordNet can be linked to other ones through one of different kinds of relations like hyponymy (specialization), hypernymy (generalization), meronymy (part-of) and so on. For a detailed and complete description of the structure of WordNet you can refer to Princeton Wordnet On-line Documentationn.

Fig.4 . The Web Interface of the Wikyoto Knowledge Editor

n http://wordnet.princeton.edu/doc

9 As we have previously said, in the KYOTO system each WordNet is composed by two sub-parts: o the Generic WordNet that cannot be modified accessing the Wikyoto Knowledge Editor, but only browsed; o the Domain WordNet that is linked to the Generic WordNet and is collaboratively built by Concept Users; they can create and modify new domain synsets and link them to the existing ones in the Generic or Domain WordNet, by exploiting the different kinds of relations present in WordNet. In the upper part of the WordNet Browser and Editor interface we can search for a synset, typing a lemma and choosing among all the synsets referred to it, that are partitioned in generic and domain ones (see the Lemma Disambiguation Box in Figure 4). For each synset, we can browse, in the WordNet Hierarchy Box, all the synsets that are related to it through a chosen relation. They are visualized in an expandable tree-view. The Term Browser and Editor is useful to interact with and edit KYOTO relevant term collections, representing a source of suggestions to create domain extensions of the WordNets: terms are extracted by the Tybot by mining the collection of KAF annotated documents. Terms are organized in specialization hierarchies; for instance, if we consider the English term 'frog' we can access the following two levels hierarchy where 'frog' is the root: frog I--- common frog I--- endemic frog I--- poison frog I--- golden poison frog I--- gopher frog I--- dusky gopher frog I--- forest frog Each term can be characterized by: - one or more possible ways to refer to it, called term forms (plurals, particular spelling or punctuation, etc.); - one or more document occurrences; - one or more associated senses, represented by synsets. As we can see from Figure 4, in the upper part of the Term Browser and Editor there is the Term Search Box, used to search for a term in the Term Base; searching is simplified thanks to an interactive suggest drop-down list. Once a term is selected, it, along with the other terms of hierarchy it belongs to, if any, is visualized in a tree-view in the Term Hierarchy Box. Every time a term is selected from the opened hierarchies, all the information describing it is loaded in the Term Information Box on the lower part of the interface: all the term forms as well as the WordNet synsets associated to a term are shown along with all the document occurrences of the same term. Concept Users can easily prune term hierarchies that are not well-formed removing terms or rearrange these hierarchies through simple drag&drop operations over the nodes. They can also delete the synsets that have not been correctly associated to a term or delete/add other term forms to a particular term.

10 3.3. Enriching WordNets with new Domain Synsets In order to show a possible WordNet extension example by exploiting the Wikyoto Knowledge Editor, we consider the English language and the environmental domain, since the environment is the test-domain considered for the KYOTO Project. Indeed two important environmental organizations are involved: the WWFo and the ECNCp. Let's suppose that we are environmentalist KYOTO Concept Users and we are interested in frogs and, in particular, in rare frog species. After having accessed the Wikyoto Knowledge Editor, we can search for the term 'frog' in the English WordNet in order to see how it is semantically contextualized. Among all the different meanings, or better all the synsets associated to the word 'frog', we load the one referring to 'any of various tailless stout-bodied amphibians with long hind limbs for leaping; semiaquatic and terrestrial species'. As shown in the right side of Figure 5, we visualize the list of all the hyponyms of the frog synset, that are all the more specific concepts present in WordNet usually referring to particular specie of frogs like the ‘tree frog’, the ‘robber frog’ and so on. Browsing the different kinds of frogs we would like to check if there are other relevant species of frog that can be useful to enrich the WordNet frogs’ classification. To get new suggestions about other possible kinds of frogs we search for the term 'frog' in the Term Browser and Editor and load the related term hierarchy (see the left side of Figure 5). As we can notice, there are seven terms that are 'frog' descendants, representing different kinds of frogs: they have been extracted by the Tybot from the collection of KYOTO parsed documents. We can immediately see that the root term 'frog' as well as other two terms in the hierarchy have been associated to at least one synset because of the little 'W' shown on the icon on the left of each of these terms. We can notice that the term 'endemic frog' is a kind of frog that is not present as a synset in WordNet, but it could be relevant to describe environment related contents and to mine environmental information, thus we decide to create and extend the English domain WordNet with a new 'endemic frog' synset. We can simply drag the term 'endemic frog' from the related term hierarchy and drop it over the more general synset of the hyponymy hierarchy visualized in the WordNet Hierarchy Box of the Knowledge Editor. We can edit the core information describing the new domain synset we want to create. We can refine its lemma, specify its part of speech and provide a descriptive gloss for ‘endemic frog’. In order to search for the gloss of the synset to be refined or to access other descriptive data, from the Knowledge Editor we can query relevant external resources like, for instance, DBPediaq. It is the Semantic Web version of Wikipedia and constitutes a sort of central semantic reference for many other datasets. From the Knowledge Editor we can query DBPedia SPARQL endpoint to easily retrieve all the meanings for the word 'frog'. We can read the short description of each of them, choose and import the correct one to easily provide the gloss for our 'endemic frog' synset. Once completed all the operations, we can confirm the creation of the new domain synset that is added to the English domain WordNet and immediately visualized among all the other hyponyms of the 'frog' synset. o http://www.wwf.org/ p http://www.ecnc.org/ q http://dbpedia.org/

11 As a consequence, from now on when the KYOTO linguistic processor parses and annotates an English document where the 'endemic frog' is mentioned, with a good probability, this term will be recognized and associated to our newly created domain synset.

Fig.5 . Creating a new English WordNet Domain synset from the term ‘endemic frog’

In this first prototype of the Knowledge Editor, we have not considered KYOTO Central Ontology, but in the upcoming KYOTO system, when a Concept User creates a new synset, he should be able to map, by mean of the Knowledge Editor, this new meaning over a possibly new language-independent domain ontological concept, defining the mapping through a dialogue-based interface, if the user is not an ontology expert. An alert concerning the creation of the new language independent domain ontological concept should be sent to notify concept users of all the languages that don't have their synset for the particular concept so as to solicit its creation in the respective WordNets. In order to access the current prototype of the Wikyoto Knowledge Editor prototype or to check for new versions, you can visit KYOTO Project Official Web Site (http://www.kyoto-project.eu/). 4. Conclusions and future works In this paper we have described, providing explanatory examples, a new wiki knowledge management environment, the Wikyoto Knowledge Editor: it is the collaborative Web environment to maintain and enrich the knowledge resources of KYOTO, a complex knowledge-driven system exploited by transational groups of users to find and share facts across different languages and cultures. The Wikyoto Knowledge Editor allows, through a Web browser, to collaboratively enrich and refine a collection of eight WordNets of different European and Asian languages all aligned to the language-independent KYOTO Central Ontology, thus providing the background knowledge exploited in the KYOTO system to mine language-independent knowledge from textual documents and share it.

12 Starting from the first prototype of the Wikyoto Knolwedge Editor just described, during the next phases of the KYOTO Project the most important new features that will be added to it are: the possibility to browse and edit the KYOTO Central Ontology, fine-tuning the mapping of the different WordNets to it; the support for domain Ontology and WordNets versioning of changes related to the actions performed when Concept Users modify them; a further simplification of the Web interface for non expert users, with the addition of tools to support a consistent global management of knowledge resources; a deeper integration of external ones as well as a stronger collaboration among the same users. Also a stronger user dissemination and a set of user evaluation tests have been planned. In conclusion, we can say that the Wikyoto Knowledge Editor, in the global context of the KYOTO system, represents an interesting and innovative example of Wiki knowledge editing tool that faces many of the fundamental issues that currently characterize the collaborative management of knowledge resources, trying to realize new easy solutions actively involving their community of users. These tasks represent core challenges to be addressed in today's knowledge-driven world. References Abraham S., Tudorache, T., Noy, N., and Musen, M. A. (2008) Customizable Workflow Support for Collaborative Ontology Development. In proceedings of the 4th International Workshop on Semantic Web Enabled Software Engineering in the 7th International Semantic Web Conference. Auer, S., Dietzold, S., Lehmann, J., and Riechert, T. (2006) Ontowiki - a tool forsocial, semantic collaboration. In proc. of 5th International Semantic Web Conference (ISWC), Athens, USA. Bai, F., and Zaoulfa, E. J. (2007) Interactive and collaborative ontology development. Khun, T. (2008) AceWiki: Collaborative Ontology Management in Controlled Natural Language. In proc. of the 3rd Semantic Wiki Workshop co-located with the 5th European Semantic Web Conference (ESWC07), Tenerife, Spain. Krötzsch, M., Vrandecic, D., and Völkel, M. (2006) Semantic MediaWiki. In proc. of the 5th International Semantic Web Conference (ISWC06), Athens. Schaffert, S. (2006) Ikewiki: A semanticwiki for collaborative knowledge management. In proc. of the 1st International Workshop on Semantic Technologies in Collaborative Applications (STICA 06), Manchester, U.K. Tudorache, T., and Noy, N. (2007) Collaborative Protégé. In proc. of the Social and Collaborative Construction of Structured Knowledge Workshop at World Wide Web Conference (WWW2007), Banff, Canada. Tudorache, T., Venditti, J., and Noy, N. (2008) Web-protege: A lightweight owl ontology editor for the web. In proc. of the OWL experiences and directions, first International Workshop in the 7th International Semantic Web Conference (ISWC08), Karlsruhe, Germany.