Has not worked for years Rated 1 out of 5 stars
I had a tab in Firebug labelled 'Reference' that did nothing. I had to go through all my extensions, disabling them to find what it was and it was this. It has not worked for years and now I remember, it was a 1-star when it did. They still offer an even more outdated version on their website. For a far better reference, right click an element and select 'Search Google (or something better) for...'