Updating from panther to leopard
Other notable features include support for writing 64-bit graphical user interface applications, an automated backup utility called Time Machine, support for Spotlight searches across multiple machines, and the inclusion of Front Row and Photo Booth, which were previously included with only some Mac models.Apple missed Leopard's release time frame as originally announced by Apple's CEO Steve Jobs.
No Mac may run an older operating system than it shipped with (links to the Mac OS X Upgrade FAQ, where at the beginning there are articles which explain why this is the case), and you need to use either the disks which came with the Mac, or newer retail disks to install Puma (10.1), Jaguar (10.2), Panther (10.3), Tiger (10.4), and Leopard (10.5) retail titles.item.142678 David Fink The problem with using a Power Book G4 on the Internet is that the latest version of the OS it will support is OS X 10.4 (Tiger), and Apple no longer supplies security updates for that version.item.142694 David Charlap David Fink wrote: "The problem with using a Power Book G4 on the Internet is that the latest version of the OS it will support is OS X 10.4 (Tiger), and Apple no longer supplies security updates for that version." Not all Power Book G4s top out at 10.4.When first discussed in June 2005, Jobs had stated that Apple intended to release Leopard at the end of 2006 or early 2007.However, the senior project marketing director for Mac OS X stated on June 11, 2007 that the existing HFS , not ZFS, will be used in Leopard.So that ultimately I could upgrade the machine as needed. item.142480 Marc Schneider A good machine; I have similar one. As I'm sure you know, don't expect speed (by today' standard).
I usually tell people that I spend so much time staring at the screen thinking (really just going "duh"), that speed really doesn't matter -- plus I am not a fast typist.
If necessary,* upgrade PB G4 system and apps no further than the latest upgrade intended for that (PPC) processor.
*Remember the farmer's motto: if it ain't broke, don't fix it.
Often a Tiger-based Mac will be a secondary machine repurposed just for this task.
On Intel-based Macs, there are people who stick with Tiger for several reasons.
Mavericks, Yosemite, and El Capitan are available for "free" (older software written for Power PC Macs may require a paid update to become compatible before installing 10.7 or later) download for those with 10.6.8 or later.