Firefox is one of the most popular web browsers for every platform. It is available for Windows, Linux, and Mac OS X, and it is as full-featured on each of those platforms. Firefox was among the first to use a tabbed environment to allow users to browse several pages in a single window. Tabs still are the norm and they work great. Firefox on the Mac has not been the fastest web browser to tell you the truth. I made the switch to Chrome after getting annoyed by long cold start times. Recent versions, however, helped Firefox to become one of the fastest browsers yet again.