Please do. But also please read the GNU Emacs info under
* Standards: (standards). GNU coding standards. * Intellectual Property:: Keeping Free Software Free * Reading Non-Free Code:: Referring to Proprietary Programs * Contributions:: Accepting Contributions
You might consider joining the GM2 Mailing list before you start coding. The mailing list may be subscribed via a web interface http://lists.nongnu.org/mailman/listinfo/gm2 or via email firstname.lastname@example.org.
Many thanks and enjoy your coding!