Hasbro releases the "Beast Wars" line in which both Autobots and Decepticons transformed into animals. This spawned a CG series that ran for three seasons.
Beast Wars was followed up by a new series called Beast Machines. Introducing a new species of Transformers called the Vehicons, the series lasted for two seasons, with Japan-exclusive spin-offs and offshoots.
Dreamwave begins an entirely new set of Transformers comics, based on the premise that the Autobots defeated the Decepticons but are attacked on their way home to Cybertron. This lasted until 2005.
Also this year, Hasbro and Takara co-produced a new 52-episode series and spin-off toy line called Transformers: Armada. It had no direct ties to the "Generation One" universe, although it featured many of the same characters.
Hasbro and Takara release the sequel to Armada - Transformers: Energon. Again it takes the form of a 52-episode cartoon series and toy line, as well as having its own comic book run.
The first ever game based on Transformers comes out on PS2, a decent third-person shooter based on the characters and storyline from Armada.
IDW publishing resurrects the "Generation One" universe in a series of special edition comics written by long-time Transformers author Simon Furman.
Hasbro and Takara co-produce Transformers: Cybertron, a follow-up to Armada and Energon.
Dreamworks releases an updated, live-action Transformers movie, directed by Michael Bay and produced by Steven Spielberg with special effects by Industrial Light and Magic. It has no direct ties to any of the previous Transformers continuities.