Why Ubuntu Linux looks different than Knoppix Linux

It's because Ubuntu uses the Gnome desktop
environment, and Knoppix uses KDE. If you like KDE and
want to use Ubuntu, there's Kubuntu, which offers both
desktop environments.

And then there's Edbuntu, which brings this friendly Linux OS to schools with a "customized school environment." I, for one, can see of no better place to use Linux than the schools, where the cost of an up-to-date commercial OS for each and every workstation is prohibitive. With Ubuntu, things can be up to date all the time, with free apps for everybody, too. And for those kids into computer technology, there's no better OS to learn from and about than an open-source Linux.

What if you have a really old computer? Try Xubuntu, a thinner version of Ubuntu without the Gnome or KDE graphical user interfaces. It requires 192 MB of memory to install but can then run on as little as 64 MB of RAM (128 MB recommended). And best of all, it takes up only 1.5 GB of hard-disc space.

And all of the Ubuntu versions are capable of dual-booting, meaning that Linux and Windows can co-exist on a single PC.