Utilitarian resources
http://www.utilitarianism.com
A large number of sources on utilitarian thinkers and thought past and present.

Howard League of Penal Reform
http://www.howardleague.org
A leading penal reform group that provides details and critical reviews of latest policy developments.

Kant on the web
http://www.hkbu.edu.hk/~ppp/Kant.html
A website with links to the major writings of retributivist thinker Immanuel Kant.

Hegel resource site
http://www.gwfhegel.org
A website with links to the major works of retributivist thinker G.W.F. Hegel.

No More Prison
http://www.alternatives2prison.ik.com
UK abolitionist website that provides some very good resources, alongside details on penal activism in the UK and links to other anti-prison groups.

ICOPA
http://www.youtube.com/watch?v=VtZY159f0p0
A fascinating 63-minute documentary on the 11th International Conference on Penal Abolition held in Tasmania in 2006.

Critical Resistance
http://www.criticalresistance.org
US abolitionist website with many important resources on penal abolitionism.

Restorative Justice Online
http://www.restorativejustice.org
Provides a useful definition and a very comprehensive listing of literature on restorative justice.