Michael Brennan's mawk. A very fast, very robust version of awk.
ftp://ftp.gnu.org/gnu/gawk/
The Free Software Foundation's version of awk, called gawk.
http://www.gnu.org/software/gawk/gawk.html
The Free Software Foundation's home page for gawk.
http://awka.sourceforge.net
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.
ftp://ftp.gnu.org/gnu/gettext/
The source code for GNU gettext. Get this if you need to produce translations for your awk programs that use gawk.