allizom is mozilla spelled backwards. Mozilla uses this domain for development like https://support.allizom.org/en-US/ for this forum. There would normally no need to access websites on this forum unless you are a tester. You can check that those pages aren't set as (multiple) homepages. You can check the homepage setting. *Options/Preferences -> Home *https://support.mozilla.org/en-US/kb/how-to-set-the-home-page Firefox supports multiple homepages separated by '|' (pipe) symbols.