The following URLs indicate where to get source code for four freely available versions of awk, and for GNU gettext .
Brian Kernighan's home page, with links to the source code for the latest version of awk from Bell Laboratories.
Michael Brennan's mawk . A very fast, very robust version of awk.
The Free Software Foundation's version of awk, called gawk.
The Free Software Foundation's home page for gawk.
The home page for awka, a translator that turns awk programs into C, compiles the generated C, and then links the object code with a library that performs the core awk functions.
The source code for GNU gettext. Get this if you need to produce translations for your awk programs that use gawk.