Congrats to the Ubuntu MATE Team!It looks like their 15.04 release will the first as an Offical Ubuntu flavor. People who are looking for more a traditional desktop look on Linux should check out Ubuntu MATE. I posted a previous video by Luigi showing Ubuntu MATE on PowerPC. So if you have a G4 or G5 there is a PPC ISO you can grab and install.
read more here
visit The Ubuntu MATE site
PowerPC ISO here
UPDATE: Ubuntu MATE will officially support PowerPC in 15.04! See their blog.