Dictionary of Algorithms, Data Structures, and Problems: Includes definitions, problem analysis, code samples, and in some cases animations.
Cheat Sheets for Developers: A directory of free cheat sheets and quick reference cards for developers. Cheat sheets are a good resource for students for remembering syntax of the programming languages they are learning. Also covers a number of other computer science areas.
Theoretical Computer Science: a free, community driven Q&A for theoretical computer scientists and researchers in related fields. You can browse existing questions and answers as well as post your own questions or provide answers to others.
ACM Tech News: Provides timely information for IT professionals three times a week.
Free Online Dictionary of Computing: An online glossary, with cross-referencing.
PCMag Encyclopedia: An online dictionary of over 20,000 terms.
TechWeb TechEncyclopedia: Another good source of definitions and brief explanations of computer-related terms.
Acronym Finder: An general-purpose acronym list.
Internet Acronym ServerAn acronym look-up.
Numerical Prefixes: The dual meanings of kilo, mega, etc.
Conversion Factors: This document defines conversions from Imperial weights and measures, as used in the U.S., to the metric system (SI units).
Unit and Base Conversion: Online tools for converting between different units and also for converting a number from one base to another.
Conversion Web Site: Collection of online converters of units and measures, plus data tables and facilities.Also contains numerous other conversion tools.
Treasure Trove of Paper Summaries: Authored by various CS grad students. The summaries themselves are a useful guide into the literature. Also, they provide a good guide on how to write a report on a paper or book.
Home Page of William Stallings