Go ahead and download it. Install it to a different directory, and test your code with both.

I have an alias that runs a (what else?) Perl script to find itself in the PATH and change it to the specified version. It writes the change to STDOUT and the alias (or batch file) can update PATH to that result. I also have aliases named perl56 and perl58 that run the specified version regardless of what's on the PATH first.

FWIW, the few things I've tried have shown no problems with ActiveState 5.8. With both available, you can still go back to the old for compatibility if needed—assign the .perl561 extension to the old perl.exe and rename any scripts that have issues.

—John