general purpose virtual servers ...
Linux-VServer allows you to create virtual private servers and security contexts which operate like a normal Linux server, but allow many independent servers to be run simultaneously in one box at full speed. All services, such as ssh, mail, Web, and databases, can be started on such a VPS, without modification, just like on any real server. Each virtual server has its own user account database and root password and doesn't interfere with other virtual servers.
How to utilize?
First you'll have to patch your kernel, to extend the existing functionality a little, and to allow a secure separation between the servers.
Then you'll need some userspace tools, to access those newly added features and to ease everyday vserver work, like starting or stopping those vservers.
Stable, Development and Experimental?
Linux-VServer is an active community project, and every day we add some new and experimental features ...
On the other hand, the code is running on several production systems, so we also try to provide a stable branch, which only contains very well tested code.
The development branch is where those experimental features are added, if they have reached a point, where we consider inclusion into the stable branch.