PROTÉGÉ-II comprises a set of tools that developers use to build intelligent software systems. One tool, called MAÎTRE, allows developers to browse through and edit domain models (ontologies). Another tool, called DASH, takes as its input a domain ontology, and generatres as its output a graphical knowledge-acquisition tool that application experts can use to enter the detailed content knowledge necessary to define new applications. Other tools in the PROTÉGÉ-II collection allow developers to define the problem-solving methods that automate application tasks by making selections from a library of reusable problem-solving-method building blocks. PROTÉGÉ-II has been used to create knowledge-acquisition tools and the associated knowledge bases for a number of applications, including the decision-support components of the T-HELPER computer-based patient record system.