Well, it sounded like a major goal in their announcing blog post:<p><i>We would like add-on development to be more like Web development: the same code should run in multiple browsers according to behavior set by standards, with comprehensive documentation available from multiple vendors. To this end, we are implementing a new, Blink-compatible API in Firefox called WebExtensions. Extension code written for Chrome, Opera, or, possibly in the future, Microsoft Edge will run in Firefox with few changes as a WebExtension.</i><p><a href="https:&#x2F;&#x2F;blog.mozilla.org&#x2F;addons&#x2F;2015&#x2F;08&#x2F;21&#x2F;the-future-of-developing-firefox-add-ons&#x2F;" rel="nofollow">https:&#x2F;&#x2F;blog.mozilla.org&#x2F;addons&#x2F;2015&#x2F;08&#x2F;21&#x2F;the-future-of-dev...</a>