Mozilla's next big move may not be adding features to Firefox, but rather removing them.
In a post on Mozilla's firefox-dev mailing list, Director of Engineering for Firefox Dave Camp outlined the bare bones of a plan to move Firefox off its legacy XML User Interface Language (XUL) architecture and onto a newer stack that more directly complements the modern Web.
"There's a huge body of shared wisdom about how to build applications on the Web," wrote Camp. "It's time to go back and examine how we can bring that wisdom back into Firefox."
Camp pointed out how XUL and its associated technologies don't receive the kind of platform attention as HTML itself, creating issues of performance and unneeded complexity. "It's harder for even experienced Web developers to get up to speed. It's further from the Web, and that doesn't help anybody."
Right now, there's no clear successor for XUL, either in terms of replacing it with or in carrying it out. However, there's the sense that a replacement is needed and a conversation needs to take place. One technology likely to be involved, Mozilla's Rust language (now in its 1.1 incarnation), has not yet been explicitly tapped to build the next generation of Firefox, but the Servo layout engine being built with Rust has long been rumored to be a candidate technology.
A post to the official Mozilla blog dated July 2 hints at more changes for Firefox, but it focuses on end-user, nontechnical details. The discussion revolved around functionality like support for HTML5 video, the WebRTC-powered Firefox Hello app, and the emphasis the company has placed on privacy.