What software packages allowing to run multiply root-accessed virtual servers/private servers on one machine are available?

I know about Ensim ServerXchange, but the quote I got from them is unfortunately out of my budget. Great product if you manage tens and hundreds of servers, but I have only 2 servers now.

I also know about VMware Workstation (cheap) and VMware GSX Server (expensive, but at least one-time fee). Anyone had any experience with GSX Server? I am trying VMware Workstation 3 beta right now and the first tests show that it is quite slow (in my test when running just 1 private server the overhead is between 30%-40% on 700 MHz machine, i.e. private server perfomance is 500 - 550 MHz).

(Added later: searching this forum archive I also found freeVSD. It is free, which is good. I am going to give it a try).

Are there other software packages allowing to run private servers I am not aware of? I am especially interested in those which do not have monthly fees associated with them.

See links: Ensim (www.ensim.com), VMware (www.vmware.com), freeVSD (www.freevsd.org)

FreeVSD only offers semi-root access, it is not true root access.

Whether you need true root access obviously depends on what application you are using. The advantage of FreeVSD is that its not emulation and therefore suffers no performence panelty.

Peter

There was a story on slashdot today regarding
virtual private servers, and the free kernel
patch that can do that & much more.
http://www.solucorp.qc.ca/miscprj/s_context.hc

Also, be sure to have a look at the freebsd jail function.