I've had so much hope in Ubiquity; let's hope this will get a nicer model for writing extensions and a "package" manager (I'd love something like Sublime2 has).
Firefox has a package manager, but Ubiquity didn't. Instead you embedded some meta tags in your webpage pointing out the Ubiquity extensions and following that page you'd get an installation.
https://addons.mozilla.org/en-US/firefox/addon/mozilla-labs-...