My Slackware (10.0-10.2) systems are runing 5.8.x because that's what they came with. My Windows PCs are running ActiveState 5.8.x because that's what they had when I installed it. At work, I'm stuck with 5.6.1 on a Solaris 9 system, which is where my 'real' Perl work runs. I don't have any plans to upgrade, as I've got a long ways to go before I need more Perl features. Although it would be nice to get the included modules up-to-date.