Serdar Yegulalp
Senior Writer

Mozilla’s Rust-based Servo browser engine inches forward

news analysis
Apr 3, 20153 mins

Next-gen Servo project more fully exploits modern multicore hardware, but don't expect it to replace Firefox any time soon

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 Servo browser engine 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.

Serdar Yegulalp

Serdar Yegulalp is a senior writer at InfoWorld. A veteran technology journalist, Serdar has been writing about computers, operating systems, databases, programming, and other information technology topics for 30 years. Before joining InfoWorld in 2013, Serdar wrote for Windows Magazine, InformationWeek, Byte, and a slew of other publications. At InfoWorld, Serdar has covered software development, devops, containerization, machine learning, and artificial intelligence, winning several B2B journalism awards including a 2024 Neal Award and a 2025 Azbee Award for best instructional content and best how-to article, respectively. He currently focuses on software development tools and technologies and major programming languages including Python, Rust, Go, Zig, and Wasm. Tune into his weekly Dev with Serdar videos for programming tips and techniques and close looks at programming libraries and tools.

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