Yet, Firefox already had an ARM64 version for Android and Linux, so this was not a major concern. This was not the case with Firefox, though, since its iOS version is little more than a wrapper around WebKit and does not use Firefox's own engine due to restrictions imposed by Apple. Usually, this is no major issue for programs that support both macOS and iOS, since all iOS devices from Apple use the ARM64 architecture.

In general, the first step in the transition to Apple Silicon for any program is to compile the code for the ARM 64 platform. Furthermore, when Apple considers the transition to the M1 complete, they will remove Rosetta 2 from their new OSes, as was the case with the original Rosetta used for transitioning from the PowerPC to the Intel platform a few years ago. While Apple Rosetta 2 binary translation technology ensures that most existing programs for macOS will be able to run on the new platform without any modifications, this will not enable them to take full advantage of the new CPU characteristics.

For complex programs, this may be no small feat, though, as Firefox engineer manager Gian-Carlo Pascotto recounted. With the introduction of Apple Silicon, macOS developers will need to port their programs to the new CPU.

Firefox m1