Rated 3 out of 5 stars

Nice add-on, but I think WikiLook (https://addons.mozilla.org/en-US/firefox/addon/7675) is better. With WikiLook you don't need a hotkey to display the popup, just hovering over a selected word for a second or two displays the popup with the definition of the word.

This review is for a previous version of the add-on (0.96).