Rated 1 out of 5 stars

Microsummaries are removed as of Firefox 6.0: https://bugzilla.mozilla.org/show_bug.cgi?id=524091

Rated 3 out of 5 stars

Can't imagine building microsummaries without this. I concur on the compatibility with FF4, but no such luck with FF5. Four stars for incredible usefulness, minus one for lack of maintenance.

Rated 5 out of 5 stars

Compatible with Firefox 4.0
In fact.. I'm using it right now with nightlies :D