Before working on improving GRUB, it's very important that you
make contact with the core GRUB developers. Things herein might be
slightly out of date or otherwise not easy to understand at first
glance. So write to <grub-devel@gnu.org> first.

For bug tracking, refer to:

  http://savannah.gnu.org/bugs/?group=grub

Our wiki also lists some areas that need work:

  http://grub.enbug.org/