Mainframe Entertainment was the Canadian animation company that created the hit CGI series ReBoot, Beast Wars: Transformers, War Planets: Shadow Raiders, and Beast Machines: Transformers. It was founded by Gavin Blair, Ian Pearson, Phil Mitchell, and the late John Grace.
They first productions were the CGI segments of the music videos Money for Nothing by Dire Straits in 1985 and Let's Get Rocked by Def Leppard in 1992, both directed by Steve Barron. Then, in late 1994, they finally released ReBoot on YTV in Canada and ABC's Saturday Morning. ReBoot was taken off ABC in 1996, so in 1997, its third season was aired only in YTV. That year, Hasbro hired them to produce a new fully-CGI television series to promote their new wave of Transformers toys called Beast Wars, which was aired as "Beasties" in Canada, likely due to a CRTC statute forbidding "War" from appearing in the title in a children's show.
In 1998, after the third season of ReBoot and second season of Beast Wars had ended, Trendmasters hired Mainframe Entertainment by creating a new series based on their War Planets toyline to promote it. Initially, it was also called War Planets, but it was renamed Shadow Raiders for similar reasons as Beasties. In 1999, after Beast Wars had ended, the War Planets toyline did not do well enough in Canada to continue the toys or the series, leading to their cancellation by mid-1999.
Mainframe moved on to producing the Beast Wars sequel series Beast Machines on FOX Kids from late 1999 to late 2000 and the final season of ReBoot as two movies on Toonami in late 2001. While Beast Wars and Beast Machines successfully concluded their story without ending on a cliffhanger, the last seasons of ReBoot and Shadow Raiders did not.