CoW: a controllable wiki

1. Why another wiki?

Scratching three itches:

adding interaction to a largish static site (15k HTML files, 40k other files)
wiki style collaborative document creation with asynchonous off-line editing
a test-bed for experiments in controlled languages for round-trip ontology engineering

2. Main features

designed from the ground up to support concurrent editing and off-line working with straightforward synchronisation using SVN

uses the YAM language, which

outputs LaTeX as well as HTML
allows paths as links (i.e. does not limit the namespace to a single directory like e.g. JSPWiki does) and consequently allows a tree-structured page store (and later graph-structured navigation via an ontology)

allows mixing of all types of files in its page store (which is just an SVN sandbox, in fact)

supports versioning and differencing via SVN, and allows other tools that manipulate SVN repositories to be used with the wiki data (e.g. SVN itself, Eclipse, ViewCVS, etc.)

optionally supports embedded CLOnE (Controlled Language for Onotology Editing), and therefore experiments with applications that store their data in semantic repositories whose schema is user-defined and maintained

3. Using SVN as a Wiki backend

No available Wiki in Java that we could find has good SVN support. Using SVN as a backend gives us:

off-line edit - simply checkout the pages and edit to your heart's content while off-line
edit with other tools, not just the web forms interface
management of authorship-related metadata such as how many lines added, difference between versions and so on
a stable and reliable versionning system that's been proved in production use by 000,000s of developers
concurrent editing

Why not JCR layered on top of SVN? Just a question of team resources and experience, the strength of the SVNKit library and so on.

4. Controlled languages and semantics

Annotating documents with semantics is not a panacea for all the problems of document retrieval, but can in certain circumstances be beneficial, especially for high value and medium or low volume content.

CoW is partly intended to be an experimental framework for a new type of website in which

the database is complemented by a knowledgebase storing semantic annotation (using OWLIM)
the knowledgebase is defined and populated using (CLOnE)
concurrent changes are managed as in CVS or SVN (check out, edit, update, merge, etc.)

This work is funded by research projects with

British Telecom (SeKT)
the BBC (PrestoSpace)
ATOS Origin (TAO)

5. Current status

CoW uses Grails and currently includes:

a wiki language with a JavaCC parser
a content persistence and versioning backend using Subversion
simple display and edit of wiki pages and other static content (with a minimal hypersonic DB to store pointers to wiki areas and user/role/permission data)
a version of the Grails Acegi (Spring security) plugin that includes editing of the user data and assigns permissions to wiki areas based on their DB id
user registration using the Captcha plugin

The system has two modes, workstation and server; the former does no user management, the latter uses the Acegi plugin.