Generative Programming advocates developing a family of systems rather than a set of single systems. Feature modeling can assist in supporting the development of such software product lines through software reuse. To our knowledge, CASE-FX is the first implementation of state-level feature modeling support within a CASE tool. Categories and Subject Descriptors D.2.2 [Software Engineering]: Design Tools and Techniques - Computer-aided software engineering (CASE); D.2.13 [Software Engineering]: Reusable Software - Domain engineering General Terms Design, Standardization Keywords CASE, feature modeling, Rational Rose-RT