You might already know this, especially the technical writers and documentation helpers out there, but I only discovered it last week. AsciiDoc uses plain text files with Wiki-like markup to generate wonderful HTML, PDF, manpage, DocBook and of course plain text documentation from one single, easy to manage file. It’s amazing, and since PDF output goes through DocBook, you get totally crisp-looking documents, including source syntax highlighting, pretty quotations and many other goodies. There is even a filter to generate sheet music from text.
Look at the “Overview and Examples” section for an idea of what this can do. I am seriously considering it as an end-user and sysadmin documentation format for leihs and MAdeK. Single-source publishing. Yummy!