These have been around for quite sometime now but newer Firefox users will find these interesting.
You can type these in the address bar and press enter to access the pages:
about:cache - Shows you some detailed stats on your disk and memory cache which includes the directory and the list of files/web pages accessed and stored there.
about:config - Pointed this out way back. Allows you to configure Firefox in-depth.
about:plugins - Lists all the installed plug-ins in your browser.
about:credits - The long-ish list of people who have helped in building our favorite browser.
about:Mozilla - It seems to be a quote from a passage in "The Book of Mozilla." You can’t find that anywhere though. Reads:
And so at last the beast fell and the unbelievers rejoiced. But all was not lost, for from the ash rose a great bird. The bird gazed down upon the unbelievers and cast fire and thunder upon them. For the beast had been reborn with its strength renewed, and the followers of Mammon cowered in horror.
