Like Google, Mozilla doesn’t want to restrict the install of add-ons to AMO only and they don’t want their users to suffer with bad add-ons that are not hosted on their site also, to balance this, the company has introduced extension signing, means every extension hosted on AMO and outside on other sites needs to be submitted to Mozilla add-ons site for a review. Once the extension passes the review and gets a signing, then only users can able to install it in the release or beta versions of Firefox browser.

Q2 in 2015 has been set as the transition period (12 weeks), during this period, Firefox (probably Firefox 39) shows a warning for unsigned extensions.

Extension signing for Firefox

“There will be a transition period of two release cycles (12 weeks total) during which unsigned extensions will only generate a warning in Firefox. After the transition period, it will not be possible to install unsigned extensions in Release or Beta versions of Firefox. There won’t be any preferences or command line options to disable this.” Mozilla rep Jorge Villalobos said in a blog post.

However, developers or users can still able to test unsigned extensions in Nightly and developer editions.

If you’re a developer of an extension that isn’t hosted on AMO, you need to follow the below procedure for signing it.

“Extension files that aren’t hosted on AMO will have to be submitted to AMO for signing. Developers will need to create accounts and a listing for their extension, which will not be public. These files will go through an automated review process and sent back signed if all checks pass. If an add-on doesn’t pass the automated tests, the developer will have the option to request the add-on to be manually checked by our review team. A full review option will also be available for non-AMO add-ons, explained further ahead.”

Here is the add-on install experience that has passed the full review looks like

Firefox full-signed add-on install experience

What’s your take on this? Share your opinions on this in the comments.