Software Infrastructure

As a starting point we made an evaluation of existing relevant software systems. In a three month selection procedure the project partners compared and evaluated a preselected subset of widely used wiki- and content management systems like Mediawiki, Typo3 or Plone implemented in different programming languages. One of the major attributes in the evaluation was an active and working open source developer community. Publishing the WissKI software as an open source project embedded in an active developer community will provide continuation of this development after the project itself has finished. The long experience gathered by the Wikipedia project shows that the way the users deal with the given software framework and get used to create content provides important input for further developments of the software. Thus, the WissKI project partners promote not only the software to a software developer community, but also the features and possibilities of the system to the content experts from different fields of research in memory institutions and beyond.

In the end of the evaluation we decided to choose the open source content management system Drupal for several reasons: Drupal is an enterprise size content management system which has a large on-line community and an extensive documentation. It comes with a wide range of functionalities for on-line communication and community building, offers a fine grained access control and supports multiple languages both in front- and back-end. Furthermore it has good capabilities to deal with multimedia files, especially images. One very important aspect was that it can be configured to behave like a wiki with revision management and unique page titles, easy linking and so on. But the main argument to use Drupal as a base for WissKI was its extensibility with modules. Every single aspect of the system can be controlled and modified by modules without touching the core system. In this way the WissKI system can reside on top of Drupal, use all  its functionalities and still benefit from patches and bug-fixes provided by the developers. Drupal requires a very common software combination (LAMP) available for windows and linux consisting of a web server (Apache), PHP and MySQL. In addition to the core system, WissKI depends on several Drupal modules.

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The WissKI system itself is implemented as several modules which can be installed and uninstalled at run-time via the standard administration interface of Drupal. As data backend a RDF triplestore is added to the drupal database. Again several triple stores were evaluated: RAP, ARC2, Jena, 4Store and many more. To keep the software environment as homogeneous as possible the used triplestore ARC2 is also implemented in PHP with a MySQL storage. ARC2 is very lightweight and high-performance triplestore that has been extended for the use in the WissKI project in consultation with the originators. The joint development of ARC2 and the WissKI system already shows that an active developer community strongly supports and hopefully outlasts the development of the WissKI project. WissKI actively supports the development of the ARC2 triple store on GIT and already provided several enhancements.