Konami

From the Super Mario Wiki

Konami
Founded	May 19, 1969
First Mario Game	Mario Roulette
Latest Mario Game	Dance Dance Revolution: Mario Mix

Konami is a third-party company that has made two Mario games: Mario Roulette and Dance Dance Revolution: Mario Mix. Konami also created the Metal Gear series, which features Solid Snake as the main character. Snake appeared as a playable character in Super Smash Bros. Brawl. Mario and Yoshi have made a cameo appearance in one of Konami's Metal Gear games.

Companies
AlphaDream | Arika | Artoon | Camelot | Capcom | CERO | DIC | ESRB | Fuse | Game Freak | Good-Feel | HAL | Hudson Soft | Intelligent Systems | Jupiter | Konami | Namco Bandai | Next Level Games | Nintendo | OFLC | Paon | PEGI | Rare | Sega | Sora Ltd. | Square Enix | St.GIGA | SUZAK Inc. | TOSE | Treasure | Valiant