See also:
Church-Turing Thesis Alonzo Church and Alan Turing formulated the thesis that computability coincides with recursivity; by Jack Copeland. http://plato.stanford.edu/entries/church-turing/
Computability Theory Directory of researchers working in computability theory, and list of open problems. http://www.nd.edu/~cholak/computability/computability.html
Hypercomputation Research Network The study of computation beyond that defined by the Turing machine, also known as super-Turing, non-standard or non-recursive computation. Links to people, resources and discussions. http://www.hypercomputation.net/
Problem Solving Environments Home Page This site contains information about Problem Solving Environments (PSEs), research, publications, and information on topics related to PSEs. http://www-cgi.cs.purdue.edu/cgi-bin/acc/pses.cgi