Mozilla is using WebAssembly-based memory sandboxing technology to improve security in the Firefox browser. Called RLBox, the technology allows Mozilla to quickly convert Firefox components to run inside a WebAssembly sandbox.
Developed by university researchers, RLBox is a toolkit for sandboxing third-party libraries. It combines a WebAssembly-based sandbox and an API to retrofit existing application code to interface with a sandboxed library. The isolation offered by RLBox is planned for inclusion in Firefox 74 on Linux and Firefox 75 on macOS, with Windows support to follow soon afterward. Firefox 74 and Firefox 75 are scheduled to arrive in March and April, respectively.