doubledouble  30 digit floating point precisino 

doubledouble implements approximately 30 decimal place floating point arithmetic. Does NOT use multipleprecision or arbitraryprecision methods, which always have a significant speed penalty. doubledouble is about a 1025 times slowdown. (Dec 2001)

FixedPoint Math in C 

From Embedded Systems magazine (04/2001): Joe Lemieux's implementation of FixedPoint Math in C with basic operators (+, , *, /). (Jul 2002)

High Precision Arithmetic Software Directory 

Contains the doubledouble precision, quaddouble precision and arbitrary precision (multiprecision) software written by David H. Bailey (LBNL), Sherry Li (LBNL) and Yozo Hida (U.C. Berkeley). This software is provided for research use. (Dec 2001)

LibTomMath  integer math/crypto library 

LibTomMath provides highly optimized and portable routines for a vast majority of multipleprecision integerbased number theoretic applications (including public key cryptography). Win32/Linux portable (Jul 2003)

LiDIA  Computational Number Theory C++ Library 

LiDIA is a C++ library for computational number theory which provides multiprecision data types and timeintensive algorithms. Includes Factorization, Lattice Basis Reduction, Number Fields, Polynomial templates, and more. (Dec 2001)

See also: Math   See Also: if you are interested in Math Precision you may find related topics in Math 
See also: Debugging   See Also: if you are interested in Math Precision you may find related topics in Debugging 
Books about Math Precision   A complete list of books on Math Precision available through Amazon.COM 