The Discontinuity Guide to the Faction Paradox series.
The very fact of your existence is a discontinuity
- Morel in The Slow Empire
In 1995, Paul Cornell, Martin Day, and Keith Topping published The Discontinuity Guide, a guide to all sorts of things about the original TV series of Doctor Who. Following this, an excellent website called The DiscContinuity Guide has provided the same kind of information about the continuing audio adventures based on the series and this site has done the same for the novels.
In 1997, the Doctor Who novel Alien Bodies by Lawrence Miles introduced what has become known in fan circles as "The War in Heaven" - a future war between the Time Lords and an unnamed enemy. It also introduced the time-travelling voodoo cult known as Faction Paradox. This scenario was explored in a number of books before being written out in 2000's The Ancestor Cell. Following this, Lawrence authorised a series of books and audios continuing the story. These books, audios, and comics, branded as Faction Paradox use pseudonyms for those some aspects of Doctor Who continuity to which they do not have the rights (e.g. the Time Lords are referred to as the "Great Houses" and the Doctor as the "Evil Renegade").