We describe an environment for building software engineering tools.The proposed Tool Generation Environment (TGE) is intended for use by skilled and experienced software engineers to construct effective CASE tools quickly and at low cost. The TGE is designed to be platform independent, multi-method, highly interoperable, and amenable to rigorous analysis. The TGE incorporates meta-CASE concepts with formal specification techniques, and uses the CDIF standard for inter-tool data interchange. We describe the architecture of the TGE and explain, with examples, how CASE tool meta-model information is represented and manipulated. Prototype implementations of TGE components are described, and directions for future research in this area are suggested.