Since the original game was made available, three expansion packs have been produced: Winter Assault in 2005, Dark Crusade in 2006 and Soulstorm in 2008. It would spawn a series of sequels that would prove to be the best-selling Warhammer 40,000 video games of all time and would serve as the entry point into the Warhammer 40,000 universe for countless fans. It was released for the PC by THQ on Septemin North America. Warhammer 40,000: Dawn of War is a real-time strategy computer game developed by Relic Entertainment based on Games Workshop's popular tabletop wargame, Warhammer 40,000.