I'm not at a startup (anymore... we got bought), but we're using Groovy for unit/functional testing. It's a nice compromise when you want something that cuts t

I'm not at a startup (anymore... we got bought), but we're using Groovy for unit/functional testing. It's a nice compromise when you want something that cuts through boilerplate with metaprogramming/duck typing but can keep tight interop with Java where you need it... and you need a quick learning curve for Java devs. That said, stack traces are horrible, debugging in Eclipse is difficult to impossible depending on how "dynamic" you get, there's no interactive debugger like pdb.set_trace() (that I know of) and the flexibility of the syntax can get out of hand quick. Great for limited use, like making mini-languages and glue for testing. Wouldn't want to support a large application written in it.