Abstract. The HeKatE Project aims at providing a complete hierarchical design and implementation framework for rules. Principal ideas of the project include an integrated hierarchical design process covering stages from conceptual, through logical to physical design. These stages are supported by speci c knowledge representation methods: ARD+, XTT2, and HMR. Practical design and implementation support using these methods is provided by the HeKatE design environment called HaDEs. A complete custom rule runtime environment HeaRT is provided to run XTT2 rule bases. The engine o ers a number of rule-base quality analysis plugins.