Can I install windows 10 on Mac G5 running leopard os?

persico256 wrote:

What OS (windows 10 ?) can I install on Mac G5 2005?

if not I want install free OS, Linux or devian , what is the best match with it?

Microsoft Windows does not have a recent PowerPC version. Not since Windows NT 4.0, NT 3.51, and such. And the NT kit that was a separate distribution for PowerPC, same as the separate Windows distributions used for Windows on Intel Itanium and DEC Alpha. A (probably still scrounge-able) Windows NT 4.0 kit for Intel won’t work here.

Here’s a list of operating systems that have (or had) PowerPC versions, though not all of those may run on a Power Mac G5:

https://en.wikipedia.org/wiki/PowerPC#Operating_systems_2

A fairly recent OpenBSD might install here, based in the following:

https://ftp.openbsd.org/pub/OpenBSD/7.3/macppc/INSTALL.macppc

Boot Camp is not involved here in any fashion.

Do you mean a PPC G5 system? Windows does not have a PPC version.

As far as Linux goes, I'm not aware of any current Linux distribution which supports PPC systems. The last time I installed Linux on a PPC Mac was many years ago and even then support was already out dated and very limited. At the time I installed Debian Jessie, but trying to find the PPC installer is difficult as they re-organized their website. Debian Jessie I believe was the last supported version of Debian for PPC, but some Debian developers did provide an installer for some later versions of Debian, although with very limited software available in the repositories. At the time I installed Debian Jessie on the PPC system, Debian Jessie was already five plus years old with at least two later Debian releases, but once I found the installer Debian Jessie was easy to install and just worked without any issues. I believe Ubuntu gave up their PPC distribution at the same time or perhaps even a few years earlier.

The hardest part will be to locate the actual Debian PPC installer as the Debian website does not make it easy to locate. Even the later unofficial PPC Debian releases were difficult to locate. There are two or three different PPC CPU architectures which is a bit confusing to know which installer you will need for the G5.