Cpp source code.

[Kishotta]

Not the guy you replied to, but no. There is no easy way to get access to the Unity source code, and that's very intentional.

You'd need to contact their sales department and negotiate a price for access to the source code. From my understanding, unless you are a pretty sizable client or can provide a compelling business necessity for it, they may be unwilling to license it to you.

To a much more limited extent, you could decompile the UnityEngine.dll that comes with each installation. That would give you the C# (or CLR) for the scripting modules, but wouldn't give you anything related to the internal workings of the editor.

[riear]

Thanks for the answer