W3 Schools: find all the Web-building tutorials you need, from basic HTML and XHTML to advanced XML, Multimedia and WAP.
DevGuru: Programmer’s quick reference resource
MSDN Online. Microsoft Developers Network provides a bounty of technical information, sample code, documentation, technical articles, and reference guides for developers using Microsoft tools, products, and technologies. It also contains standards and release information, as well as samples, downloads, and tutorials
Marttindale’s Calculators Online
Learn C/C++ Today. After furnishing some background and tools required for C and C++, this site lists several tutorials available on the Web.
Linux Documentation Project (LDP). LDP provides access to Linux guides (book length), HOWTOs (documents on specific subjects), FAQs (questions with answers), man pages (help with individual commands), and the “Linux Gazette” (a magazine with tips and tricks).
UNIXhelp for Users. This site contains helpful information for users of the UNIX operating system. It is organized by tasks, commands, concepts, and utilities, and includes a searchable glossary.
ReviewBooth Contains reviews of computer hardware and software
Symantec AntiVirus Research Center: virus encyclopedia
CODE Visual Parallel Programming System