Office desktop cannot install Fedora Core 6 (don't know why, anaconda occupied 99% CPU time without any output), and luckily today is release day of Ubuntu 6.10 (Edgy Eft), so I would like to give it a try.
My office desktop only got 256Mb RAM, it tooks about 10 minutes for Ubuntu live CD to boot into the GNOME desktop. And Ubuntu server seems slow and busy, so in the installation stage, which required download some langauge support packages, it tooks nearly one hour to finish.
After installation, reboot and the familiar Ubuntu screen came up, the default installation is very simliar to Fedora Core 6 but the GNOME version is 2.16.1 instead of FC6's 2.16.0, and the theme seems a bit better look than FC6.
But the default installation of Ubuntu has NO support of AIGLX, but luckily, I found the method to install the beryl and emerald packages, after some apt-get and config file tweaks, I got the latest AIGLX enabled desktop!