DDBase

Declare (formerly DDK, DisLog Developers' Kit) is a collection of libraries developed in SWI-Prolog including features from data and knowledge engineering, databases (relational, XML, deductive), Semantic Web, and non-monotonic reasoning; DDBase is part of Declare, too.

The Declarative Toolkit Declare

The Declare project started with a system DisLog for non-monotonic reasoning in disjunctive deductive databases. A variety of additional packages for different purposes has been added, e.g.

• management and querying of XML-data,
• reasoning about programs in knowledge and software engineering,
• analysis and visualisation of stock information and data from sports,
• management of data in bio-informatics, artificial intelligence in games.

Most applications are equipped with graphical user interfaces developed in object-oriented (e.g., Java or the extension XPCE of SWI-Prolog) or in declarative markup languages (e.g., HTML 5 or the XML User Interface Language XUL from the Mozilla project). Declare can be downloaded from http://www1.informatik.uni-wuerzburg.de/database/Declare.tgz (about 9 MB).

The Deductive Database System DDBase

DDBase uses the Datalog extension Datalog^s with function symbols, where rule bodies can contain embedded Prolog calls and default negation. Bottom-up and top-down evaluation are possible in one system: Datalog^s can evaluate extended Datalog programs, i.e. logic programs with Prolog syntax, in a bottom-up style; it is designed to evaluate embedded Prolog calls in a top-down manner.