"Suppression of Dissent" website
Brian Martin, an important fighter against suppression for more than 25 years, maintains this excellent, chock-full, site. It contains many analyses of suppression, discussions of how to fight it, and a lot of documentation.
The New School for Pluralistic Anti-Capitalist Education, a new educational project in NYC I am involved with. The first semester (Spring 2005) was VERY SUCCESSFUL, a real blow for freedom. The site has a good and ever-growing pluralism page.
International Working Group on Value Theory
Founded in 1993 by Alan Freeman and me. The site contains a very large archive of papers from many perspectives, the IWGVT Scholarship Guidelines -- the purpose of which is to encourage pluralistic, critical engagement -- and more.
Common Wheel Collective
The featured item is the CWC's book-in-progress on collective process, containing insightful analyis of often unrecognized suppressive behaviors, attitudes, and group dynamics.
International Confederation of Associations for Pluralism in Economics. A network of 30+ heterodox economics groups that seeks to foster intellectual pluralism and a sense of collective purpose and strength.