After two years in development, the web-based Google Earth 9.0 debuted earlier this year. The new version runs entirely in the web browser, but it only works in Google Chrome. This is because it used Portable Native Client (NaCl), a technology that allows C and C++ code to run in the Chrome browser. Since no other browser bothered implementing NaCl, the Earth web app was exclusive to Chrome.
That is now changing, as the Twitter account for Google Earth revealed that Firefox support is in the works:
— Google Earth (@googleearth) October 27, 2017
You might recall that Chrome added support for WebAssembly earlier this year, which is another technology for running compiled native code in browsers. The difference is that WebAssembly is a cross-browser standard being developed by multiple companies, while NaCl was created by Google specifically for Chrome. WebAssembly is already supported by Firefox, Chrome, Safari, and Opera (with experimental support in Edge).
In a blog post, the Google Earth team said that it had been working since April to port Earth to WebAssembly. This opens up the web app to work on more browsers, and as such, the team has been extensively testing Earth in Firefox. There's no ETA for the release date, but it's nice to see progress being made.