I'm searching for something on the level of GNU extensions for C, but a little beyond (some basic data structure management). Best would be something BSD/MIT licensed.
If there is something for just strings containing GNU extensions equivalents plus adding some more it would be great.
I would prefer something that can be simply compiled into a project (no external libraries) based totally on the C standard (ANSI C89 if possible).
Edit: its for an OpenSource project that has a weird license, so no GPL code can't be added and working with plain K&R/ANSI C is pure pain.