Rated 5 out of 5 stars
Just found this by a desperate search for a Tagsifter replacement. You made my day!
AMO should really host extensions in a way that invites collaboration (like github). Extension development should be a community thing. It should be possible to adopt abandoned extensions and keep the name. Abandonware is the biggest problem with extensions. Incompatible abandoned extensions keep people from updating Firefox, which leads Mozilla people to develop evil fantasies about scraping extensions altogether.