Mozilla has shipped Firefox 55 Beta and Developer Edition today. As you may already know, Developer Edition is now based on the beta build instead of the separate Aurora (alpha) channel. Check out our Firefox 55 compatibility notes to get prepared for the final version coming early August.
The most important change in 55 is probably the click-to-activate requirement for Flash content. If your site is still relying on the outdated plug-in, it’s really time to consider moving to latest standard technologies to offer the best possible user experience.
By the way, we are planning a site design refresh (and more) next month so stay tuned!