libmpdec is a complete C implementation of the General Decimal Arithmetic Specification. The specification, written by Mike Cowlishaw from IBM, defines a general purpose arbitrary precision data type together with rigorously specified functions and rounding behavior. As described in the scope section of the specification, libmpdec will - with minor restrictions - also conform to the IEEE 754-2008 Standard for Floating-Point Arithmetic, provided that the appropriate context parameters are set.

libmpdec++ is a complete C++ implementation of the General Decimal Arithmetic Specification. The library frees users from manual memory management and has an easy API with inline operators. libmpdec++ has a thread local context for inline operators and other functions that use the implicit context.