With the release of Firefox Quantum on November 14, 2017, we officially entered a WebExtensions-only world for add-on development. While that event was certainly the news of the day, Firefox 58 quietly entered Beta and a host of new APIs and improvements landed. As always, documentation for the APIs discussed here can be found on MDN Web Docs. Additional Theme API The API around themes continues t
![Extensions in Firefox 58 – Mozilla Add-ons Community Blog](https://cdn-ak-scissors.b.st-hatena.com/image/square/a15181ccf08bed7ce718be8ec0023dff1d257646/height=288;version=1;width=512/https%3A%2F%2Fblog.mozilla.org%2Faddons%2Ffiles%2F2017%2F11%2Fimage2-252x214.png)