Ubuntu
This is my first post from a brand new world.
I have just installed Ubuntu 5.10 ("Breezy") in my G3 iBook, and so far I just love it. Fast, stable, incredibly easy to set up. The whole install took 45 minutes (10 minutes copying stuff from the CD to the hard disk, and then 35 minutes configuring itself). Ubuntu recognized every bit of hardware of this machine, from the Airport card to the trackpad and the Ethernet adapter. It comes with OpenOffice, GIMP and much more pre-installed, and I really find it easy to use. Very intuitive user interface, really great operating system. And free and open source.
Now I'm following the instructions in http://www.fo64.com/articles/2005/10/20/rails-on-breezy for installing Ruby on Rails on this brave new system.
I really look forward to use Ubuntu in my everyday work. I plan to use it as the default system for this laptop for a while. Stay tuned...