I haven't tried it myself yet but for those more versed in Linux dabbling, someone's released a new flavour of Linux based off Debian specifically for PPC systems:
https://fienixppc.blogspot.com/
G5 specific files here:
http://repo.powerprogress.org/yocto...kSIvXh2uT-Hpp2y5K4e4xVQVpksFivaaHb-Y0Q4ufKA4g
https://fienixppc.blogspot.com/
G5 specific files here:
http://repo.powerprogress.org/yocto...kSIvXh2uT-Hpp2y5K4e4xVQVpksFivaaHb-Y0Q4ufKA4g