Capsicum: practical capabilities for UNIX

what is a capability-based security system ?

http://www.cl.cam.ac.uk/research/security/capsicum/

and are other kernels(openbsd, netbsd,linux, TRON ...) implementing it.

I have not really understood the implementations and how to use them as an administrator.

Is it something like selinux? or does it affects at the level of dbus, IPC, CORBA ...

An introduction to FreeBSD-Capsicum ::
http://lackingrhoticity.blogspot.com...-capsicum.html

Have only briefly looked at the link but would guess it's to do with the way you grant access/permissions to objects. So it then would have more links with SELinux (which restricts access in addition to restrictions due to traditional Unix ugo permissions) than dbus etc, but... it might regulate not only normal files but also networking etc...