Python - Python is a clear and powerful object-oriented programming language, comparable to Perl, Ruby, Scheme, or Java.
Grit Game Engine - The Grit Game Engine is an MIT-Licensed Open Source Game Engine that is highly scriptable via Lua.
Rust - A safe, concurrent, practical language
libtwo - All-purpose c++ app prototyping library, focused towards live graphical apps and games
Java - A concurrent, class-based, object-oriented, language specifically designed to have as few implementation dependencies as possible
MOS - Lightweight game engine.