Ubuntu Dapper is gearing up to be a rock solid enterprise release of what is already a very good operating system. Ubuntu has also been getting much attention in these forums, mainly from people who have taken the Debian package and tried to hack it to install on Ubuntu. I would love to see official Ubuntu packages as I think Zimbra and Ubuntu are taking the open source world by storm. I think they would do wonders together.
sudo apt-get install zimbra anyone?