GNU awk. It is the GNU Project's implementation of the AWK programming language - a pattern scanning and processing language. AWK is an acronym for Aho,Weinberger and Kernighan. It is supposed to be compatible with the POSIX standard and the standard UNIX version of awk. It also has a number of GNU specific extensions.
GNU awk was written by Paul Rubin and Jay Fenlason. It also has been ported to DOS, VMS, Atari ST, OS/2 and Amiga, in addition to the different varieties of UNIX.