Activision

Activision Publishing, Inc. is an American video game publisher based in California. It is one largest third-party video game publishers in the world. Activision published Sonic games betwen 1999 and the very early 2000's as previous publisher Expert Software had merged with the company.

Published Sonic games

 * Sonic Action Pack
 * Sonic Action 4 Pack
 * Twin Pack: Sonic 3D Blast / Sonic R
 * Twin Pack: Sonic CD / Sonic & Knuckles Collection
 * Twin Pack: Sega Smash Pack / Sega Smash Pack 2
 * Sonic Adventure DX: Director's Cut