I'd put RB + SmaCC among the lot. But I consider that really non-trivial : the pattern language of RB (and the underlying pattern matching and unification algorithm) is top notch, and how SmaCC builds on RB to virtually generate code / optimise code / then compile is nothing short of amazing.

SmaCC comes with a pattern matching/unification algorithm over ASTs + auto-generation of AST code + visitor + tree equality + the equivalent of Flex/Bison(*) + a GUI in 11401 lines of code.