Abstract Service: An archive of abstracts of logic articles at the Institute for Logic, University of Vienna.
Classical Logic: Introduction to classical logic, including completeness and Löwenheim-Skolem theorems; by Stewart Shapiro.
Computability Logic Homepage: Main online source on computability logic, - a recently emerged formal theory of computational tasks and resources. Maintained by G.Japaridze.
Logic: Open Encyclopedia entry. Hierarchically organized by subareas.
Math Front: LO Logic: Front end for the logic section of the mathematics e-print arXiv.
Mathematical Logic and Foundations: From The Mathematical Atlas, a `resource` of mathematics maintained by David Rusin. Extensive resources related to logic and set theory.
