Hello, I'm very very sorry to ask that. I am de backoffice developer from 15 years in industrt, and I'm a user of firefox since years. I still do not understand how to USE/LAUNCH an installed extension in Firefox. This question does not sound wierd to me, but it's very hard to find an answer. And the Firefox Menu doesn't help at all. For example I've juste installed Bookmark Dupes. I've spent a long time to understand how to launch this "application" on my firefox installation. What to type in URL, where to go in menus, to remove my duplicated bookmarks please. Can you help me ? Gilles