** '''Why Rust?''' Existing code from Servo, parallel performance.
* Replace the XML parser
** '''Why Rust?''' Parses untrusted input, replaces expat, a 3rd-party library with a history of frequent security vulnerabilities.
* WebMIDI: {{bug|1201593}}, {{bug|1201596}}, {{bug|1201598}}
* Gamepad code: {{bug|1286699}}