Rated 5 out of 5 stars
Excellent addon! It would be awesome if menus could stay open also with the addons 'History Button' and 'Undo Close Tab Replacement'.This review is for a previous version of the add-on (184.108.40.206-signed).
Stay-Open Menu 2.0b2 supports the 'History Button' add-on. Currently available at https://addons.mozilla.org/firefox/addon/stay-open-menu/versions/ or wait for the final 2.0 release.
Support for 'Undo Close Tab Replacement' may be considered for some future release.