ZdNetItalia : CMath for Windows

Use a math library for C++
CMath is a comprehensive library for complex arithmetics and mathematics. In the first place, CMath is intended as a high-quality replacement of the complex class libraries that come with C++ compilers. In addition, all functions of CMath may be called from C, without the need to use C++. Implementation in Assembly language (as opposed to the C++ code of the common complex class libraries) provides superior speed, accuracy, and safety. Each of the three floating-point accuracies (float, double, and extended) is given its own, optimized version of each function. This 16-bit version is for use with Windows 3.x. The ZDNet library also contains a 32-bit version for Windows 95/98/NT and a DOS 5.0 version.