Some people have tried out a preview release of MacPAF, and there is an issue with pre-Mac OS X 10.4 systems, but the developer is working on it. A preview release for Mac OS X 10.4 (Tiger) users may be made available, while issues are worked out with pre 10.4 systems.
Some issues have been found already and are being addressed, but a preview release will be made available in the next few days.
You can keep an eye on this here, or at the developer’s home page.