The Language Evolver Lever — Tool Demonstration —

Since many domains are constantly evolving, the associated domain specific languages (DSL) inevitably have to evolve too, to retain their value. But the evolution of a DSL can be very expensive, since existing words of the language (i.e. programs) and tools have to be adapted according to the changes of the DSL itself. In such cases, these costs seriously limit the adoption of DSLs.This paper presents Lever, a tool for the evolutionary development of DSLs. Lever aims at making evolutionary changes to a DSL much cheaper by automating the adaptation of the DSL parser as well as existing words and providing additional support for the correct adaptation of existing tools (e.g. program generators). This way, Lever simplifies DSL maintenance and paves the ground for bottom-up DSL development.