Discworld is a comic fantasy book series by English author Sir Terry Pratchett, set on the Discworld, a flat world balanced on the backs of four elephants which, in turn, stand on the back of a giant turtle, Great A'Tuin.
You can find more info on wikipedia, or even discworld&pratchett wiki, or better yet - READ IT! :)
The Discworld Companion has around 344 pages.
The Art of Discworld was created in 2004.
Discworld MUD happened in 1991.
Discworld MUD was created in 1991.
Discworld Noir happened in 1999.
GURPS Discworld happened in 1998.
GURPS Discworld was created in 1998.
The Science of Discworld was created in 1999.
Sir Terry Pratchett wrote Discworld.
There is but it's a MUD (text based game). There are also several Discworld board games (such as "Thud!") and Discworld video games for PC, Playstation, etc (such as "Discworld Noir").
The Discworld Mapp was created on 1995-11-09.
Discworld Noir was created on 1999-07-05.