CR-LIBM, a correctly rounded elementary function library. We present a new elementary function library, called CR-LIBM. This library implements the various functions defined by the Ansi99 C standard. It provides correctly rounded functions: the returned result is always the floating-point number that is closest to the exact result. When writing this library, our primarily goal was to certify correct rounding, and make it reasonably fast, and with a low utilisation of memory. Hence, our library can be used without any problem on real-scale problems.