Comment by electroly

It's not. Open up any of the .c files and you'll see lots of references to Cocoa. One of the comments refers to Cocoa by name! This is using objc_msgSend to call into Cocoa. You'd have to squint your eyes pretty hard for the claim in the readme to be true. What it doesn't have is Objective-C code, which is different than not having Cocoa.