What is GNU/Linux?
Why do you keep saying GNU/Linux instead of just Linux?!
It can be long winded to say, long winded to type and long winded to read, but Richard Stallman asked us to do that. Richard Stallman started the free (as in freedom) software movement 25 years ago and has been campaigning for freedoms for computer users ever since, so I think it's the least we can do in respect of his sacrifices.
Richard insists on the GNU part because Linux is just a kernel, just the core of the system. On top of that runs many GNU programs that are part of the GNU project and hundreds more programs besides that. 'GNU' is a reminder of the goal of the GNU project: to produce software that's not just convenient, and not just produced using a superior collaborative method, but software that does not seek control over its users.
Why do you run GNU/Linux on your PowerPC?
If you are running GNU/Linux on your computer, here's where you can tell us why.
I bought my Mac Mini to use it primarily as a home server. I previously had an extremely noisy PC that I used to prop pillows up against just so I could think straight. When I mentioned this, a colleague recommended a Mac Mini to me. It has been a great investment: super quiet, low power and so small you could put it in a drawer (if it had some ventilation).
This website is currently running on my G4 Mac Mini!
As for software though, OSX just seemed to get in the way. It would dial in to the Internet but there seemed to be no way to get it to redial after the connection dropped. The firewall was difficult for me to configure since I had experience with GNU/Linux's IPTables. Darwin seemed like a stripped down version of the GNU/Linux I was used to, so after a short time I switched, mainly for the sake of convenience.
Lately GNU/Linux has become a bit more of a moral issue to me. I know that the more we support black-box software that we can't learn from and can't improve, the more we will regret it in the long run. When you use software that doesn't respect your freedom, you allow the developer of that software to disrespect you, and you give them power over you. At the same time, the development of better and better software is greatly retarded because of the secrecy. The same code has to be written over and over again because we can't all work together.
This is why I love GNU/Linux: it's software that respects me, doesn't restrict me, I can help improve it, it's convenient and easy to use, and it continuously advances the state of the art for everyone.