Mozilla has hidden various configuration and diagnostic information in its internal about pages. Some of the important about pages are ,
This page contains a verse from the Book of Mozilla.This was first introduced in 1994.
The contents of this page has already been discussed here.
You’ll find Firefox’s crash reports on the about:crashes page. Click a crash report and it’ll be submitted to Mozilla, where you can view information about it.If you’re struggling with a crash, you can use the information here to figure out what the problem is. Googling up some of the crash messages might help you determine the problem.
Firefox includes website-specific permissions, which you can manage for a single website by right-clicking on a web page selecting View Page Info. About:permissions shows you all this information in one place.
Here you can find all the about pages in Firefox. Try out each one. It will help you to use Firefox efficiently.