I’m trying to avoiding losing access to hundreds of data files on a 2009 Macintosh––running OS 10.5.8.
Im sure you could find a work around but i doubt the actual program will run in linux
More the. Likely not
There are emulators that will run windows apps on a linux install. However, have not heard of Linux running Mac programs. Unless there is a windows version of the same program, you may be out of luck.
Mac programs might use cross platform programming languages, but the binaries(the machine code the runs the program) will be system dependent. The source code for Mac programs are not open. You might get lucky with some apps that can run well on a Unix kernel in which case, can run on both Mac and Linux. However, there is no reliable method of installing Mac programs on a Linux system.
If you need to use Mac apps, stick with Mac.