Nintendo

Nintendo is a video game console manufacturer and software company. Before the Dreamcast was discontinued, Sega was one of it's largest competitors, but Sega now releases software for Nintendo's home and handheld consoles. At the height of the Genesis' popularity, Sega created the slogan "Genesis does what Nintendon't!" and mentioned all the things the Genesis/Mega Drive could do what the Nintendo Entertainment System and Super Nintendo Entertainment System, like Blast Processing and 16-bit graphics. The two would also insult each other in their games, like a cancelled boss from Alex Kidd in Shinobi World was called "Mari-Oh". And in Donkey Kong Country 2, Sonic's shoes are seen next to a trashcan under the "No Hopes" section.

Nintendo is/was SEGA's rival company. Mario is Nintendo's mascot. After SEGA stopped making it's own consoles in 2001, it joined Nintendo and 3 other company's for it's games. SEGA (or Nintendo) asked Nintendo (or SEGA) to put Mario (or Sonic) and their friends for a challenge at the Beijing 2008 Olympic Games in Mario and Sonic at the Olympic Games. Sonic also joined Nintendo's Super Smash Bros. Brawl and the Nintendo Power magizine's.

Nintendo software with Sega content

 * Mario & Sonic at the Olympic Games (co-developed with Sega)
 * Super Smash Bros. Brawl