So, I've been wondering how I can code for the HL2 Beta. Does anyone know where I can start? I know this might be a big task but I want to test stuff in it.
The easy way:Firstly, you need to download the source code from
here.
Then, you need to install Visual Studio and then open the .sln file.
Press CTRL+ALT+L to make the Solution Explorer appear and edit the code that you want to.
Finally, press CTRL+SHIFT+B to compile the binaries.