HeadsetsIn2014 :
Any good ANSI C Compilers that are free and easy to install?
There are plenty
GCC for various POSIX environments
GCC through Cygwin on Windows (not recommended)
MinGW on Windows (recommended)
Visual Studio has full ANSI C support and strong C99 support as of Visual Studio 2013. Visual C++ Express is freely available
ICC is freely available for non-commercial use. Highly recommended by yours truly. Supports Windows and Linux.
Clang/LLVM has excellent C and C++ support across the board for all major language revisions. Available for most POSIX compliant operating systems.