• Browser engine written in Rust
• Designed for parallelism and safety
• Designed for embedding
• Probably a mobile product

• All modern engines designed pre-2000
• Difficult to experiment or fundamentally change
• Security and performance are hard

• Important for mobile platforms
• Prevent arbitrary tree access via type system
• Parallel layout only interacts with children
• Work stealing task pool, shared queue

• Web developers learning to avoid sync layout, eg:

  node.style.left = elem.getBoundingClientRect().right + 5;

• Run layout and script simultaneously
• Layout sees consistent DOM, script mutates "shadow" DOM (copy-on-write)

• C++ memory model responsible for many exploits
• Rust neutralizes them (use after free, iterator invalidation)
• Task isolation
• Process isolation
• NaCL?

• Write Rust code (learn Rust, hack Servo (good first bugs))
• Write JS/CSS code (test suite is small; integrating w3c tests)
• Build and test Servo, file bugs (nightly builds soon)
• Watch mozilla.dev.servo mailing list for news

• Fix acid2/acid3/testharness.js blockers
• Implement missing DOM APIs
• Implement missing CSS features
• Make Servo build and/or run on Windows

Josh Matthews, Platform Engineer

• @lastontheboat
• josh@joshmatthews.net

Slides: http://joshmatthews.net/fosdemservo/