On: TXL: a language for text structural transformation...

[enqk]

There is a free software analogue in development called COLM.

http://www.colm.net/open-source/colm/

[evacchi → enqk]

With respect to Program Transformation, I'd point out Stratego/Spoofax [1] and Kiama [2]

  [1] http://strategoxt.org/Spoofax  
  [2] https://code.google.com/p/kiama/