@evildictaitor:

C is also the least common denominator in that pretty much every language out there can call into it without any major problem. That makes it ideal for libraries that need to be used by a lot of different applications that may not all be written in the same language.

It's also one of the most portable languages out there as well, there are C code bases that can be compiled and used on every platform out there big, small, and rarely used. Pretty much every processor family has a C compiler available.