From The Mathematical Atlas, a resource of mathematics maintained by David Rusin. Extensive resources related to logic and set theory.
Front end for the logic section of the mathematics e-print arXiv.
Compares the mind to advanced computers and artificial intelligence, as Goedel would possibly view them.
Introduction to classical logic, including completeness and Löwenheim-Skolem theorems; by Stewart Shapiro.
A rich collection of links to logic-related websites.
Hyper-textbook for students by V. Detlovs and K. Podnieks.
Main online source on computability logic - a recently emerged formal theory of computational tasks and resources. Maintained by G.Japaridze.
Open Encyclopedia entry. Hierarchically organized by subareas.