Sony Interactive Entertainment

Sony is a company that manufactures consoles such as the PSP, the PlayStation 2, and the PlayStation 3. Sega began publishing Sonic games on Sony consoles in 2003.

Console Wars
During the fifth and sixth generations, Sony and Sega were publishing consoles at the same time. The consoles in their war included:
 * PlayStation VS. Sega Saturn (fifth generation)
 * PlayStation 2 VS. Sega Dreamcast (sixth generation)

During the fifth generation, the PlayStation ultimately beat out the Sega Saturn in sales, and during the sixth generation, Sega was forced to cancel production of the Dreamcast because the PlayStation 2 was beating it in sales, badly. After that, Sega ultimately became a third-party publishing company.