TitanFall VPK Tool for Modding

[Tally]

So it's source engine + proprietary map format (also source engine is proprietary ^^)? What I've seen in Portal 2, Squirrel can be used in REPL-modus, so code-snippets can be executed at runtime (which is very useful for learning), but really nice stuff like Client-Scripting is not possible (e.g. like in GMod with Lua or CoDScript in CoD WaW).

No, not Source engine + new map format. The 3D renderer is proprietary as well. Source is 32 bit DX9; TitanFall's engine is 64 bit DX11. Also, the netcode is proprietary, designed especially to be used with MS Azure cloud technology.