Section VIII—C99 Numeric Computational Enhancements
Historically, FORTRAN has been the premier language for numerical scientific and engineering computation. C90 brought C computational methods into closer agreement with FORTRAN. For example, the specification of floating-point characteristics used in float.h is based on the model developed by the FORTRAN standardization committee. The C99 standard continues the work of enhancing C's appropriateness for computational work.
The IEC Floating-Point Standard
The International Electotechnical Committee (IEC) has published a standard for floating-point calculations (IEC 60559). The standard includes discussion of floating-point formats, precision, NaNs, infinities, rounding practices, conversions, ...