Annotated Pratchett File is an effort by Leo Breebaart with help of Mike Kew and lots of Terry Pratchett fans to create comprehensive list of Discworld (and other Pratchett works) trivia, annotations, joke explanations etc. It is available in various formats, including plain text one, but quite strangely formatted and quite hard to convert in other formats (like ebook ones, for example: EPUB, MOBI etc). This was the reason for me to convert plain text version to reStructuredText (or rST for short), which is is one of the best (or just the best) lightweight markup language. You can convert it to HTML, LaTeX, PDF, ODT, EPUB and most probably lots of other formats, whichever tickles your fancy most.