Selenium_tutorial is a project mainly written in ..., it's free.
A tutorial document for Selenium.
To generate an XHTML document, run
$ a2x -f xhtml --icons --icons-dir=/usr/local/etc/asciidoc/images/icons selenium_tutorial.asciidoc
or,
$ asciidoc -a iconsdir=/usr/local/etc/asciidoc/images/icons selenium_tutorial.asciidoc