libvirt - The virtualization API

libvirt is a toolkit to interact with the virtualization
capabilities of recent versions of Linux (and other OSes).

Most dependencies are autodetected and having the required
libs in place will build the respective features automatically.

The group can be specified at build time like this:
VIRTGROUP=somegroup ./libvirt.SlackBuild (default: users)

If you want to start the libvirt daemon at boot, add this
to /etc/rc.d/rc.local

# Start libvirt:
if [ -x /etc/rc.d/rc.libvirt ]; then
  /etc/rc.d/rc.libvirt start
fi

Have a look at the commented part of rc.libvirt for some gotchas.