This is a free, online textbook. "On the 16th May 2009 the Mozilla community got together for a one-day sprint to copy-edit and polish the manual. Lastly, on the 16th of July 2009, the Mozilla community once again came together to update this manual for Firefox 3.5. This consisted of simple things such as updating screenshots to major jobs such as writing about new Features for this release. We would like to thank all who participated for there hard work to create this excellent resource."