Logic and Foundations

Classical Logic - Introduction to classical logic, including completeness and Löwenheim-Skolem theorems; by Stewart Shapiro.
plato.stanford.edu/entries/logic-classical/

Computability Logic Homepage - Main online source on computability logic - a recently emerged formal theory of computational tasks and resources. Maintained by G.Japaridze.
www.cis.upenn.edu/~giorgi/cl.html

Introduction to Mathematical Logic - Hyper-textbook for students by V. Detlovs and K. Podnieks.
www.ltn.lv/~podnieks/mlog/ml.htm

Mathematical Logic and Foundations - From The Mathematical Atlas, a resource of mathematics maintained by David Rusin. Extensive resources related to logic and set theory.
www.math.niu.edu/~rusin/known-math/index/03-XX.html

Mathematical Logic around the World - A rich collection of links to logic-related websites.
www.uni-bonn.de/logic/world.html

Mind Versus Goedel by Damjan Bojadziev - Compares the mind to advanced computers and artificial intelligence, as Goedel would possibly view them.
nl.ijs.si/~damjan/g-m-c.html