d3web-Core is main platform API (application programing interface) for the development of knowledge-based applications. 
The platform is available as a collection of Java libraries providing a sophisticated plugin architecture.

A number of components is already included in d3web-Core:
* General representation and persistence of terminological knowledge to represent question (inputs) and solutions (outputs).
* Reasoning engines and persistence for strong problem-solving methods including
** Decision trees
** Scoring rules
** Temporal rules
** DiaFlux models
** Set-covering models
** Scoring tables

The reasoning engine and persistence components for problem-solving knowledge including decision trees, (heuristic) rules, set-covering models and diagnostic flowcharts.