Firefox 68 Integrates BigInt Support
More details on the BigInt support coming to Firefox 68 can be found via this blog post by developer Andy Wingo.
Firefox 68.0 is currently in beta with the official release expected in early July. Firefox 68.0 is also slated to offer enhancements to different UI elements, a "Recommended Extensions" program to find endorsed extensions, expanded color-space support, and a rewritten AwesomeBar using just HTML/CSS/JS. More details on the 68.0 beta changes via the release notes.