adons.Mozilla.org, which we simply call as AMO — that hosts add-ons for Firefox, Thunderbird –has got a visual refresh. Mozilla to launch this new design with Firefox 48. The current design has been in place since 2011 with minor design changes. What you’re seeing the screenshot below is a quick redesign of the site, and it will remain until the large overhaul is complete.

The company has recorded the every design change in a user style using  Stylish, if you want to see the below design right now in Firefox, you need to install Stylish first and then this userstyle.

add-ons.mozilla.org new look