There are 2 repositories under rom-hack topic.
A C# 2D Pokémon game engine and map editor.
Anarchistic Collaborative TV Game but better
MD+ Patch for Streets of Rage 1
Modification of Pokémon Red/Blue where Squirtle is replaced with the unreasonably adorable Oshawott~
Pokemon fire red, but oak is a demon, gary tries to murder you at age two, and pokemon are weapons. (its actually just changing the text.)
Pokémon Rainbow Amnesty - A Pokémon Emerald ROM hack