Quadriga is a web-application that acts as a clearing-house for text annotations -- in the form of contextualized triples, or “quadruples,” that form complex graphs -- generated with the Vogon desktop application, and as an environment for managing text-annotation projects. It relies on a central authentication system for user authentication, a dictionary service (Wordpower) and an authority file service (Conceptpower). Quadriga can connect to a DSpace repository, allowing users to select items stored in the repository for annotation. Quadriga can use standard graphs to map quadruples onto conventional semantic graphs that can be submitted to a triple store, and used for interactive websites and visualizations.

Technical details:
Quadriga is a Java web-application that can be deployed in a servlet container such as Apache Tomcat. It uses the Spring framework and stores its data in a relational database such as MySQL.