Well, CopyPaste Pro absolutely does not launch under 10.5.6, and ScriptSoftware has neither developed a working version or even mentioned plans to do so. In fact, they've been pretty silent about the whole problem. So it seems like abandonware at this point. So, if you want OS X Leopard and CopyPaste, you have to choose between not upgrading your software beyond 10.5.5, or not using CopyPaste. Keep this in mind if you're thinking of installing it.

Additionally, I've never liked this "Pro" version of CopyPaste, which lacked the functionality of earlier versions of CopyPaste (such as the "+ yType" or even Classic versions, which melded seamlessly with the OS). It always seemed to not play very nicely with the Leopard clipboard, and often would cause you to have to hit "command C" multiple times to actually get something to copy, if that method would work at all. I really dislike the fact that I had to pay for a whole new version, for what felt like a downgrade.

This is all very unfortunate, as I long was a user and fan of this system addition, which I've been using for over 10 years. Now I'm looking at alternatives like PasteBoard Pro, etc, since it looks like I'm going to be forced to migrate at this point.