[jpd]

Isn't libc just a set of libraries and therefore not considered a runtime environment? C does have a small runtime environment, but I'd say it's the existence of the function call stack, as well as the on_exit system that's built into the core language.

[ori_b]

As well as things like floating point and large integer emulation, startup code, etc. __divdi3, for example, divides 64 bit integers on i386.

See /usr/lib/x86_64-linux-gnu/{crt1.o,crti.o,crtn.o,gcrt1.o,Mcrt1.o,Srct1.o}.

[mseepgood]

On Windows it's even called "Microsoft Visual C Run-Time" (MSVCRT): http://en.wikipedia.org/wiki/Windows_library_files#Msvcrt.dl...