Although it is based on Ubuntu (currently using 8.10, of course), Linux Mint has its own desktop theme, menu system, package manager, update manager and lots more.
If you didn't know going in that it was based on Ubuntu, even an experienced Linux user might not notice it.
One of the objectives of Linux Mint is to include a variety of proprietary and non-open source packages which are not included in the Ubuntu base distribution. I noticed this right away, as several of the packages which I normally have to download and install myself on Ubuntu were already there, such as Sun Java 6, Adobe Flash, Thunderbird and Citrix Receiver (even the latest, version 11!). But there is a lot more, too: lots of multimedia stuff, such as Quick Time, Real Player and Windows Media plugins for Firefox, and audio and video players and recorders. There are Mint-customised versions of firewalls, backup utilities, net nannies, and various other common utilities.
