Nowadays, most Apple computers contain an Intel CPU and current versions of MacOSX are no longer available for PowerPC-based Apple computers. Nevertheless, we got one (and only one) request to put back the support for PowerPC Macs.
For the time being, we will support them, even if you cannot get Java 1.6 (with its incredible enhancements in performance) for such computers.
If you are interested, download it, but please also read the section labeled Limited PowerPC (G4/G5) Mac support in the MacOSX tips.