Nintendo Research & Development 2
From the Super Mario Wiki
Nintendo Research & Development 2 (often abbreviated as Nintendo R&D2) was one of Nintendo's first internal development team. The division focused on hardware development and porting games. It was headed by Masayuki Uemura, the designer of the NES and SNES.
In 2004, all of the R&D departments were disolved due to a corporate restructuring. Most of the staff were folded into Nintendo EAD or the newly-created Nintendo Software Planning & Development group.
Mario games developed by Nintendo R&D 2