Rated 4 out of 5 stars
Relating to the below comment which refers to a Bugzilla attachment - a saner way to obtain the attachment (if you wish to trust this user's edits...) is to view the page here: https://bugzilla.mozilla.org/show_bug.cgi?id=227922
Otherwise I have used this extension and liked it very much.
I shall use it again now because I wish to also use SyncPlaces which does not get along with Linkification for some reason.
It would be grand if the original author would jump in here and update this to avoid the need for users to hack it instead...
No longer necessary
I've updated the extension to be compatible with the latest version of Firefox.