Frege's Logic, Theorem, and Foundations for Arithmetic
Stanford Encyclopedia article on Frege's work on the foundations of mathematics.
http://plato.stanford.edu/entries/frege-logic/

Foundations of Computing Science
Universität Kaiserslautern, Fachbereich Informatik. Research and education in foundations of computer science. Staff, projects, publications.
http://www-madlener.informatik.uni-kl.de/ag-madlener_en.html

Practical Foundations of Mathematics
An account of the foundations of mathematics (algebra) and theoretical computer science, from a modern constructive viewpoint by Paul Taylor. Published by Cambridge University Press. HTML approximation.
http://www.dcs.qmw.ac.uk/~pt/Practical_Foundations/html/summary.html

Foundations of Mathematics
Reviews the foundations of mathematics with reference materials structured as content pages of a book. Includes links to expository materials.
http://sakharov.net/foundation.html

Foundations of Computational Mathematics (FoCM)
A nonprofit organization that supports and promotes research on foundations of computational mathematics.
http://www.focm.net/

Workshop on Logical Foundations of an Adaptive Security Infrastructure (WOLFASI)
A sub-workshop of the LICS Foundations of Computer Security (FCS'04) Workshop, LICS'04. Turku, Finland; 12--13 July 2004.
http://www.aero.org/wolfasi/

(Italy) LADSEB-CNR - Ontological Foundations
Research lab, led by Nicola Guarino, working on ontologies in knowledge representation, conceptual modeling, and information systems.
http://www.loa-cnr.it/

Foundations of Quantum Chromodynamics
A set of postscript lecture notes on the foundations of Quantum Chromodynamics.
http://arxiv.org/abs/hep-ph/9901412

Intuitionistic Topology and Foundations of Constructive Mathematics
frank waaldijk's math page on constructive mathematics, intuitionism and intuitionistic topology
http://home.hetnet.nl/~sufra/mathematics.html

Michigan, University of
mathematics graduate program
http://www.math.lsa.umich.edu/research/logic/