ARRL - The national association for Amateur Radio

Slashdot - Tech. News

NewsForge - Linux/OpenSource online Newspaper

Linux

The Linux Kernel Archives

DistroWatch - Linux distribution info

SAMBA - Windows, Linux networking

KDE - K Desktop Environment

LinuxQuestions - Linux help forum

Server

Apache - Open Source Web Server and other Web Server software

PHP - Web Scripting Language

MySQL - The World's most popular open source database

Programming

Sourceforge - world's largest Open Source software development website

Freshmeat.net - Open Source software development website (not as large as sourceforge)


Ruby - CrossPlatform and Internet Scripting Language

Ruby Central - web resource for everything to do with the Ruby language

RubyForge - open source Ruby projects

Other

Maxim IC

Microchip - PICmicro Microcontroller

Parallax - Home of the Basic Stamp Microcontroller

CrustCrawler - Robotic Design & Development

Lynxmotion - robot kits and components