Doctor Who has been around for 50 years and has one of the biggest fandoms behind it ranging in age so it’s not surprising that many spin-offs have been created based around the BBC TV show.
Despite being of the air for most of the 1990s the BBC were still supportive of Doctor Who in other media. The BBC started releasing new official story books and experimenting with animated episodes on the newly formed BBC website.
When Doctor Who returned in 2005 the BBC continued to be experimental. in 2006 there were TARDISODES, mini prequels to each episode of series 2. More recently these have returned in for forms of mini episodes. New animations have also been created including Dreamland and downloadable games from the BBC website.
Death Comes to Time (2001)
Real Time (2002)
Scream of the Shalka (2003)
BBC DVD start animating missing episodes
The Infinite Quest
The Adventure Games
BBV and Reeltime Pictures produced several unofficial stories straight to video including an Auton series and Downtime which featured the Yeti. In the 1960s two movies were created from Dalekmania unconnected with the BBC TV series. More recently in 2009 Bob Baker and Paul Tams gave K9 his own spin-off show with a second series in the works.
Doctor Who has always features heavily on CBBC in 2006 The Sarah Jane Adventures was commisioned aimed more at the younger viewers. Totally Doctor Who ran for two series looking behind the scenes. Blue Peter has always been very supportive of Doctor Who right from the 1960s.
There have been several different ranges of Doctor Who books. Some of the main ranges have been produced by Target Books (1970s+), Virgin Books (1990s) and BBC Books (1996+). There have been several Doctor Who annuals and some K9 and Dalek ones as well.
In 1999 Big Finish got the license to produce official Doctor Who audio spin-offs including Doctors and Companions from the BBC TV Series. The Big Finish Audios are hugely popular.