SUSE is one of the oldest Linux distros, originating in Germany. It was originally based on Slackware but borrowed elements of Red Hat in particular RPM. The company has been one of the most successful European Linux vendors. They were taken over by the American network firm Novell who have used the SUSE distro as their leap pad into the Linux world.
Since taking over, the "SuSE Linux" name has become "SUSE Linux" and a fully open and community driven version OpenSUSE has been released.
Most recently Novell entered into a pact with Microsoft which did the company a considerable amount of damage in the open source community.
More information can be found at: http://www.novell.com/linux/