* Encoding detector: {{bug|1551276}} (shipped in Firefox 73)
** '''Why Rust?''' Builds upon encoding_rs, has tiny FFI surface, subject matter prone to accesses past the bounds of a buffer, potentially parallelizable with Rayon.
* [https://github.com/mozilla/dogear/ Dogear] a bookmark merger for Sync. Shipped pref'd-off in {{bug|1482608}} (Firefox 68), enabled by default in {{bug|1588005}} (Firefox 72)
** '''Why Rust?''' A single performant and safe implementation which is shared between desktop and the bookmarks engine in [https://github.com/mozilla/application-services/tree/master/components/places application-services]
=== In progress ===