OpenRA

I'd like to start modding, cuz I did a lot of RULES modding on RA, but I need to know how to open and edit a .yaml file to do that. Anybody got any good programs or methods on how to do this?

Any help is appreciated.

Eh, I have a problem. I install your mod per the instructions you provided, but the game just crashes on the initial loading screen. Any thoughts? I would really like to play your mod.