Keep Firefox Open When Closing the Last Tab

The new Firefox 3.5 release brought a lot of great features, but one annoyance sent reader Mark looking for a solution: When you close the last tab, the browser closes instead of opening a blank tab.

Changing the behaviour back to the way it used to work is very simple: just type about:config into the address bar and find the browser.tabs.closeWindowWithLastTab entry in the list—using the filter makes it easy. Once you've found that key, double-click on it to change the value from true to false, and Firefox should no longer close when you close the last tab.