Firebug 1.8 compatible with Firefox 5.0 has been released and I would like to get this opportunity and introduce some new features in this version. Firebug 1.8 has been also uploaded to AMO, but it can take some time to appear. First of all, check out the following compatibility table: Firefox 3.6 with Firebug 1.7.3 Firefox 4.0 with Firebug 1.7.3 Firefox 5.0 with Firebug 1.8 (and also Firebug 1.7.