Capsicum - practical capabilities for UNIX
http://www.cl.cam.ac.uk/research/security/capsicum/
http://www.lightbluetouchpaper.org/2010/08/12/capsicum-practical-capabilities-for-unix/ (server disappeared; Google cache)
http://lackingrhoticity.blogspot.com/2010/10/process-descriptors-in-freebsd-capsicum.html
http://www.cl.cam.ac.uk/research/security/capsicum/slides/20100811-usenix-capsicum.pdf / http://www.youtube.com/watch?v=raNx9L4VH2k