As it preps for what it calls “a major release” later this year, Mozilla (News – Alert) is mulling how to build the next generation of Firefox, its HTML5-ready Web browser. The answers to that question include making it more, well, Web-based, by stripping out legacy code and adding more cutting-edge features.

It may be counterintuitive, but Firefox is actually built on an aging technology called XML User Interface Language (XUL). In a post on Mozilla's Firefox-dev mailing list, Firefox director of engineering, Dave Camp, noted that as a legacy technology with no update in sight, it lags behind the needs of the modern Web and attracts very little developer interest. As a result, it leads to performance declines and increased complexity—and it will soon be written out of Firefox entirely.

“Back in the early Mozilla days, XUL was our attempt to fill the gaps HTML had for building large-scale Web applications,” Camp said. “Over time, the Web – and app development for the Web – has evolved its own set of standards and technologies; we should follow it.”

As it moves away from XUL, one of the goals is to increase service agility, shortening the amount of time it takes to develop and roll out new features and security patches.

“The industry has continually evolved how it deploys code to users, and today it isn’t done on an 18-week cycle,” Camp said. “We think there are big wins to be had in shortening the time that new features reaches users. Critical fixes should ship to users in minutes, not days.”

The company also reiterated Firefox’ commitment to open technologies, name-checking Firefox Hello, the WebRTC in-browser video chat tool that was made in partnership with Telefonica (News – Alert). “We continue to pioneer open standards including WebVR, WebGL and WebRTC to advance the Web as the development platform,” it said in a separate posting.

While it works on modernizing its code, Mozilla said that it is also working on a number of upgrade plans for the browser, including delivering it to new platforms, such as iOS and Windows 10, “where we will provide an independent and high-performing alternative to the stock browser.” Firefox’ focus will continue to be on rich Web experiences like HTML5 video playback and game performance, and it’s also experimenting with improvements to private browsing—a hot topic in the post-Edward Snowden era.

"There's a huge body of shared wisdom about how to build applications on the Web," Camp said. "It's time to go back and examine how we can bring that wisdom back into Firefox."