Main code location

[RainMaker]

Hi, above all I will say that I am French, , sory if i do misspellings and ask me if you don't undertand something.

I'm interested to mode/edit the WZ files. I already seen majority of files, but i didn't (or almost no) found any code, just some funciton already etablished, or some variables. Where are the main files ?
I'm starting the code to, so maybe i just didn't recognize its.

PS : if someone could tell me where I can edit my signature, i didn't found it on the User Control Panel