High Quality Content by WIKIPEDIA articles! f2c is the name of a program to convert Fortran 77 to C code, developed at Bell Laboratories. The standalone f2c program was based on the core of the first complete Fortran 77 compiler to be implemented, the "f77" program by Feldman and Weinberger. Because the f77 compiler was itself written in C and relied on a C compiler back end to complete its final compilation step, it and its derivatives like f2c were much more portable than compilers generating machine code directly.