Re:Mozilla’s Add-on Policy Is Hostile to Open Source
by msujaws on Tuesday November 25, 2014 @06:01PM
(#8660306)
Add-ons can be distributed outside of AMO. A secondary (more scary) dialog is shown before the add-on can be installed, but users can click past it to get to the add-on.
PDF.js uses this approach actually. See "Development version" at https://github.com/mozilla/pdf.js/ as an example.