Since it is a maintenance release, Firebug 1.10.5 does not introduce new features. The developer has worked on improving the stability of the app and has repaired a set of five issues. The new revision has been tested with Firefox 16.
First on the list of repairs is the fact that the location list in the Script panel can now be filtered. In previous Firebug builds the first line starting with the specified letter would be highlighted.
Another fix addresses the failure to open Firebug in pop-up windows. Also repaired is the problem with the first-run page when Firebug would be updated, which would not open until Firefox web browser received a restart. This happened because of the new update mechanism in Firefox, which touched on add-ons as well and worked in the background.
On Linux, the new release should be able to properly show scripts that come from iframes. The full changelog for this release is available on this page. Download Firebug.