:qa closes the current window (because Vim habits are hard to break and shouldn't be destructive). :exit quits the app.

pentadactyl/NEWS

@@ -90,6 +90,8 @@
         and linking to source code locations). [b4]
       - :downloads now opens a download list in the multi-line output
         buffer. Added -sort flag. [b6][b7]
+      - :qa closes only the current window, per Vim. [b7]
+      - Added :exit command. [b7]
       - Added :dlclear command. [b7]
       - :extensions has been replaced with a more powerful :addons. [b6]
       - :javascript! now opens a Read Eval Print Loop. [b6]