The cool kids that own Macs might want to check out this tutorial on setting up a DocBook environment on OSX. I love DocBook for creating technical documentation. Because DocBook documents are XML or SGML they are easily translated into many published formats.

To learn more about DocBook, visit DocBook.org, but in a nutshell:

DocBook provides a system for writing structured documents using SGML or XML. It is particularly well-suited to books and papers about computer hardware and software, though it is by no means limited to them.

In short, DocBook is an easy-to-understand and widely used DTD. Dozens of organizations use DocBook for millions of pages of documentation, in various print and online formats, worldwide.