Domain specific languages (DSL), high-level programming languages with constructs expressing precisely the concepts of a specific application domain, can be used to implement entire applications as DSL scripts. DSLs are growing in popularity, and are proving to be an effective means of improving productivity. However, people writing applications in domain specific languages are typically without debugging support and must resort to unpleasant, primitive methods to debug their scripts. Many tools (e.g., parser-generators) support DSL implementation, but a debugger for a DSL still must be built from scratch, without tool support. This project develops a re-usable infrastructure for building DSL debuggers. By analyzing interpreter-based implementations of DSLs, a uniform, general model of the most common features of the data structures found within the run-times of interpreters is developed. The model is then used to leverage a reusable, retargetable debugging framework (comprising a GUI, command interpretation machinery, etc.) that can be added at low cost to an existing interpreter to provide debugging support.