C code for orientation and incircle tests using adaptive-precision floating-point arithmetic
http://www.cs.cmu.edu/~quake/robust.html
Power-of-two real and complex FFT software that is faster, and more accurate, than conventional iterative implementation of one-dimensional FFTs. Based on a propietary algorithm.
http://www.davis-inc.com/rmftl
Source code and links for many different FFT implementations and related information.
http://www.jjj.de/fxt/
Professional C++ mesh generators. Includes product information and news releases.
http://www.computing-objects.com/en/meshtools.html
A package of Fortran subprograms for the fast Fourier transform of periodic and other symmetric sequences.
http://www.netlib.org/fftpack/
Fast and robust C++ code available under GNU license. Handles arbitrary dimensions, and has high numerical stability.
http://www.inf.ethz.ch/personal/gaertner/miniball.html
By David O'Halloran. The Welchel phase-rotation FFT is a new form of the fast Fourier transform (FFT) that replaces data movement at runtime with equivalent multiplications by precomputed constants. The result is an FFT that is easy to pipeline.
http://www-2.cs.cmu.edu/afs/cs.cmu.edu/project/iwarp/member/fx/public/www/phase1.html
Summary of major CG problems and implementations of their solutions
http://www.cs.sunysb.edu/~algorith/major_section/1.6.shtml