High Quality Content by WIKIPEDIA articles! GNU MPFR (for GNU Multiple Precision Floating-Point Reliably) is a portable C library for arbitrary-precision binary floating-point computation with correct rounding, based on GNU Multi-Precision Library. The computation is both efficient and has a well-defined semantics. It copies the ideas from the ANSI/IEEE-754 standard for fixed-precision floating-point arithmetic. More precisely, its main features are: