Mozilla Servo
The latest browser built by Mozilla Research called Servo is close to becoming reality, with a post from one of the team's developers on the organization's forum confirming a first release should land sometime in June this year.

Servo is a cross-platform browser engine that will run on ARM operating systems (including Android) as well as on x64 platforms including Linux, OS X and Windows. It is designed to take advantage of parallelism in order to achieve optimum performance on today's multi-core systems.

What parallelism means in a browser is that the browser's independent components such as rendering, HTML parsing, layout and other jobs are handled by isolated tasks, which helps with both performance and stability.

According to a post on the developer mailing list by research engineer Paul Rouget, the team hopes to have a functional alpha out in June so people can start testing it to provide feedback – but it won't be for everyday use for months.

Rouget states his wish for Servo "to be capable of running github, duckduckgo, hackernews and reddit," adding that "we're close, but there are still several rendering and functional issue for each of these websites."

Servo is intended to be used in Firefox, but the project also includes a new web browser confusingly called Browser.html. This project implements the browser itself in HTML, and uses a runtime called Graphene for building native applications in HTML. A further twist is that developers can build Browser.html using Gecko, the existing browser engine in Firefox, as an alternative to using Servo.

The long term plan is to "incrementally replace components in Gecko with ones written in Rust and shared with Servo," according to the Roadmap, so that eventually Gecko and Servo may be almost the same thing. The process of incorporating Rust-based components into Gecko is dubbed Oxidation.