Solaris

I have a nice Ultra 10 (440 MHz, 1 GB RAM, 40 GB Disk, Elite3D m6 Graphics), which probably needs a new install. Currently it is running Solaris 10 with Java Desktop. Imho Java Desktop slows the computer a little bit down. Since a few days a have also a SunPCi II card.

Now I want to reinstall the computer. I have DVDs for Solaris 9 and for Solaris 10 and I'm not sure, which one should I use. Will Solaris 9 run faster as Solaris 10 on an Ultra 10? Do I need ZFS on a computer with a single harddisk? Is CDE more responsive than Java Desktop? SunPCi II runs out of the box only on Solaris 9, but with some extra work also on Solaris 10.

Most of the time I will do some programming in C/C++ on this machine, but only for fun, probably also some 3D graphics. The computer will have an internet connection, but not for web surfing.

Go with the latest version of Solaris 10. You can download it from the Oracle Solaris website.

I wouldn't suggest you use ZFS on a system with that little ram.

Normally there is both CDE and Java Desktop installed.
You can switch the desktop at the graphical login screen.