For some, Mozilla's most intriguing Web project isn't the next version of Firefox -- or any version of Firefox, for that matter. It's an entirely new Web browser engine, code-named Servo, written in Mozilla's Rust programming language and intended to fully exploit modern, multicore hardware.
Earlier this week, Servo's development team released a new iteration of the project with an all-new UI -- reminiscent of the tabbed interfaces found in modern browsers -- built using the first full 1.0 release of Rust.
Don't ditch your existing browser, though. Servo is a fast-moving prototype technology, not (yet) a product, and it needs to be built manually from many different pieces. Plus, even with all that work, it currently runs on only Linux, OS X, or Android; no Windows port exists yet.
Mozilla Research Mozilla's Servo browser engine, written in Rust, is meant to render HTML all the faster on modern hardware, but Servo hasn't yet been deployed as anything other than a research project.
Mozilla claims Rust has been built from the inside out for concurrent, low-level programming on modern, multicore hardware. Servo is something of a proof-of-concept project for the language that demonstrates Rust's ability to write software that not only takes advantage of current CPUs but is more secure by default than C. The HTML parser written in Rust for Servo, for instance, is billed as "[avoiding] the most notorious security problems from C, but has performance similar to a parser written in C."
Aside from benefiting from Rust's memory safety and speed, Servo's professed technological advantage over other browser engines is its ability to render multiple elements for a Web page's layout in parallel. Browser engines typically do all their work in a thread bound to a single CPU core; Servo is intended to vault over that limitation.
The rendering speed of a browser engine isn't the only thing that makes it fast, though. Websites have become as dependent on JavaScript as they have on HTML, so accelerating JavaScript performance has been the focus of much recent work on speeding up browsers. The most recent build of the Chromium project, for instance, optimizes the way JavaScript is parsed and cached to further speed page load times.
Mozilla so far has refrained from making concrete plans for Servo -- or Rust -- to formally succeed Firefox or its use of C/C++. For the time being, at least, Firefox remains Mozilla's browser of choice.