I am the author of Sledgehammer.

Other golfing languages I have used: Jelly, Pyth, Dyalog APL, TI-BASIC

Non-golfing languages: Python, Java, C++, Mathematica

My best code-golf answers:

• http://codegolf.stackexchange.com/questions/3434/shortest-game-of-life/51975#51975
• http://codegolf.stackexchange.com/questions/52547/minimal-nethack/52564#52564