As you may have heard, there are a lot of changes coming up for add-on development. In the next 12-18 months, we will transition to WebExtensions as the standard for creating add-ons. Over the same period of time, existing methods for add-on development such as XUL/XPCOM will be deprecated. Multi-process Firefox (aka Electrolysis, or e10s) is also rolling out, which means some developers will have to update their add-on more than once. All this on the heels of add-on signing.

In the past few weeks, we’ve been gathering all the information and resources we could to help developers navigate the upcoming changes. We’re also lining up new content so we can continue to keep everyone informed and supported during this adjustment period.

Everything we’ve collected so far is here. A few notable pieces of information you’ll find:

• The emails we created based on the developer profiles that were identified with the help of the add-on reviewer are going out shortly.
• A survey is available for you to tell us which WebExtension APIs you need, so we can better prioritize them.
• A timeline of changes is available that includes dates to the best of our knowledge. This is a working doc and will be updated as we learn of new information.
• If you haven’t already, add the Developer Calendar to see upcoming meetings, blog posts, and office hours. We will also be adding release milestones to the calendar in the coming weeks.
• Resources and documentation related to the transitions are added here as they’re created. We have more content queued up, and as you can see we could use even more. If you’re interested in writing about your experience creating a WebExtension add-on, or becoming e10s compatible, or anything else that others might find relevant, please sign up here.

We’ll keep releasing information over the coming months as they become available. If you have ideas or would like to pitch in, please reach out to us. We’re here to help.

https://blog.mozilla.org/addons/2016/03/10/developer-support-for-changes-in-add-on-development/