According to the recent TIOBE index (February 2012), Java is still the #1 active programming language in the world, even though it has been losing ground to C# (.NET) and Objective-C (Apple's devices). The importance to model-based testing and Conformiq is that we use Java as the language for system models that drive test generation. Some other vendors use proprietary languages, or more obscure ones such as, for instance, OCL or TTCN-3. Neither one makes the top 100 list. Remember to ask your prospective MBT vendor about the language(s) used in the vendor's tooling. Relying on a language with a very small user community could mean resource shortages and excessive training costs later.