My Best Programming Resources Online

I have a number of online resources that I consult when I need to gain knowledge or I believe are useful, I have questions or I want latest programming news.
I use only free resources and tools that don't require registration.

• WIKIPEDIA - this is by far the best encyclopedia ever. When I need to find an entry level information about any subject this is the first place I start looking at.
• STACKOVERFLOW - great programming forum, very professional and well moderated. I did find in many occasions very good answers to my questions.
• DZONE - programming resources and latest programming news
• JAVA ALLTOP - Java programming news
• CYBERCITI- Linux blog
• JAVA LANGUAGE SPECIFICATIONS - all Java language specifications
• APACHE - Java open source projects
• APACHE MAVEN  - Apache Maven website
• DVLPRS - famous programmers blogs and tweets
• SLASHDOT  - technology related news website
• REDDIT - social news  website, I read mostly compsci
• CPLUSPLUS  - C++ online resource
• GOOGLE C++ GUIDE - interesting C++ guide
• DEV GURU- JavaScript, HTML, CSS, XML, Server-side reference
• W3C WEBED WIKI (this site has a self-teaching curriculum as well as reference material): HTML, CSS reference
• W3C SPECIFICATIONS: HTML4, HTML5, CSS, DOM Tech Reports reference
• DEVGURU- JavaScript, HTML, CSS, XML, Server-side reference
• OWASP PROJECT  - the open web application security project
• WIKI MOZILLA SECURE CODING GUIDELINES - web security guidelines by Mozilla
• DEVELOPER YAHOO SECURITY - web security guidelines by Mozilla
• PYTHON - Python official website
• INTRODUCTION TO ALGORITHMS - iTunes introduction to algorithms lectures from MIT University but one can find many free lectures related to programming
• POSTGRESQL - Postgres official website
• W3SCHOOLS - SQL tutorial and tutorials to most web technologies
• SQLOPTIMIZATIONSSCHOOL - tutorial on SQL optimization
• LDAP GURU - LDAP programming guidelines
• DOFACTORY DESIGN PATTERNS - design pattern tutorial
• GOOGLE CODE UNIVERSITY - sample course content and tutorials for Computer Science 
• OHLOH - software directory, combining community-driven content with a unique source code crawler that monitors up-to-date development activity. 
• FINDJAR  - JAR search engine
• DOWNRIGHTNOW - popular services status

Great search engines:

• GOOGLE - best search engine
• WOLFRAMALPHA - computational knowledge

I will add more resources here as I find them.