Software-related

• suckless.org - Makers of Quality Software
• cat-v.org - A font of essential wisdom; heed it well.
• catb.org - esr's homepage - includes The Art of Unix Programming, The Cathedral and the Bazaar, and other good works
• Armed & Dangerous - esr's blog - good posts, good comments, people smarter than me
• The Jargon File - A better induction into the history and mindset of hacker culture is hard to find