Mozilla launched the first browser specifically built for developers known as Firefox Developer Edition, that offers access to tools and platform features before they hit the main release channel.
Now, the current Firefox 78 Developer Edition browser comes with a new regular expressions (RegExps) engine, which makes it easier to support modern RegExps features.
As the company rewrote Irregexp to use its own APIs, this made it possible to work with the new engine, though it was harder to import new upstream features, which over time, Mozilla fell behind in support for new ES2018 RegExp features.
The new approach, a new shim layer for IrregExp to provide full access to Google V8 functionality, from code generation and memory allocation to utility functions and data structures. Thereby, making SpiderMonkey to gain stronger foundation for future RegExp support, one that allow the SpiderMonkey team to bring new RegEx syntax more easier.
Future projection for the new engine
Mozilla's effort has resulted in full support for all ECMAScript RegExp features and the company is hopeful that its work on the new engine can be the basis for RegExp in Firefox for years ahead.
Therefore, the new RegExp engine closes the gap with regular expression features in ECMAScript. Firefox Developer Edition, which features latest developer tools in beta, can be accessed directly from mozilla.org.