This is an sh compatible file to be sourced in non-GNU systems (Solaris, AIX, HP-UX, FreeBSD, OpenBSD) to use GNU Coreutils, GNU Diff and GNU Make in your shell and scripts.
I found the original script at http://tomayko.com/writings/gnu-is-killing-solaris sometime in 2008.
Originally this was a gist located at https://gist.github.com/palopezv/1225563