"Diablo: Hellfire is an expansion pack that Sierra On-Line (now known as Sierra Entertainment) produced for the video game Diablo. It was released in 1997 and developed by Synergistic Software, a Sierra division. Hellfire is the only authorized expansion pack released for Diablo. Blizzard Entertainment has never released a first-party expansion for Diablo. The original game was later re-released alongside Hellfire in 1998 in a bundle called Diablo + Hellfire."