Firebird Tabbrowser Extensions

Tabbrowser Extensions for Mozilla Firebird is wonderful. It can make external applications open links in the background and in new tabs (rather than in new windows or instead of the existing page) - Preferences>Advanced>Window Mode>Use multiple browsers only when I open them - and can display a confirmation dialog box when you try and close a window that has multiple tabs open. Many other features too, particularly handy if you're getting used to Safari.