We are still in the testing phases for getting IDL to run on the new Apple Silicon ARM-based chips. There is currently no timeline on when support will be added, or even if it will be added.

Is there any update to this reply now 16 months later? I have searched the web site looking for information as to what platforms IDL can use, but can't find any. Does IDL run on M1 macs, and if so is it native or by emulation?

Platform support is always listed here: https://www.l3harrisgeospatial.com/Support/Self-Help-Tools/Help-Articles/Help-Articles-Detail/ArtMID/10220/ArticleID/18488/Platform-and-Feature-Support-for-Current-and-Previous-Versions
The M1 Chip is supported through Rosetta 2 emulation and it has been supported since IDL 8.8.1.
You might also find this help article useful:
https://www.l3harrisgeospatial.com/Support/Self-Help-Tools/Help-Articles/Help-Articles-Detail/ArtMID/10220/ArticleID/24094/Overview-Readme-File-for-IDL-881-and-ENVI-561-SP1-for-Mac-and-Other-Related-Information

IDL 8.8.2 for MacOS is still built for x86-64 architecture only and seems to run under Rosetta on Silicon Macs.
I am attempting to build shared libraries for use with call_external() from C and Fortran sources but found that the system-installed LLVM compiler and gcc-mp-12 (installed via MacPorts) only support arm64 targets.
This breaks development of those shared libraries that have been in use for over 20 years.
I can still use x86-64 bundles built on my old Intel-based Mac for IDL 8.7 but they may become incompatible with the latest version of IDL.
Any advice on how to build shared libraries from C and Fortran sources for the x64-64 architecture for use with call_external?

Has there been any progress on providing native support for IDL on ARM64 processors (M1) ? I am in the same situation as Lutz above in that I can no longer use my fortran libraries with the call_external routine... my only solution is to keep two computers running in my office, one M1 for all my work, and one older x86_64 just for IDL... not an ideal arrangement...

We are actively developing a version of IDL that will run natively on Apple Silicon. This ARM-native version of IDL should come sometime in 2023, possibly as early as the next release which is 8.9. However, it wouldn't be surprising to see it arrive slightly later.

Has the platform support for IDL 8.9 been updated? This page (https://www.l3harrisgeospatial.com/Support/Self-Help-Tools/Help-Articles/Help-Articles-Detail/ArtMID/10220/ArticleID/24309/Platform-Support-for-ENVI-57-and-IDL-89#IDLPlatformSupport) has feature support for 8.9, but platform support is for 8.8.3.

My concern is with native support for Macs running Apple Silicon cpus and also with macOS versions greater than 12. New Macs ship with v13, and I'm sure v14 will be out this fall.

Thanks, Ken Bowman

I'm checked that Help page now and it appears to be up to date (no mention of IDL 8.8.3). It is possible we updated it since you posted a few weeks ago.

With that said, IDL 8.9 does not yet natively support Apple Silicon chips but it will in the near-future. No ETA on that ARM64 version of IDL yet, though. Still hoping for a 2023 release.

As far as MacOS version support, IDL 8.9 officially supports MacOS 11.3+ and 12.x. I do not know of any specific MacOS 13 issues and it should work fine there as well. There is a hard requirement for 11.3+ though --- IDL 8.9 will not install on prior versions.