I don't have any experience in 64 bit perl beyond "it worked for me". But then, I wasn't doing something suicidal like using threads. My statement was more based on having watched windows and "Linux" flop around on the x86 64-bit beach as they attempted to drag themselves out of the 32-bit sea. So to speak. Linux and Perl have been 64-bit clean since before x86-64 existed, but there's no guarantees that other code on the system is clean and won't interfere in weird ways.

Are there any resources in particular you'd recommend discussing what to avoid in Perl on a 64-bit machine?

Don't use source filters. Also, don't use threads. Keep away from extensions written in C, since most C programmers still can't understand why they shouldn't store pointers in INTs.

More generally, (system) threads are a bad solution for most problems. If you want to download a lot of files, for instance, you'll be better served using asynchronous calls than threads. For starters, your programs won't crash.

Edit: use something like this instead: forks