• CSS Reset, a starting point for making browsers act more consistently
• A timeline of CSS module activity
• CSS Color Equivalents Table
• Color Blender, which lets you blend two colors together
• The URL Decoder/Encoder, which lets you URL-encode strings of text, or turn URL-encoded text into plainer strings
• S5, the Simple Standards-Based Slide Show System
• HYDESim, the High-Yield Detonation Effect Simulator
• Information about Rebecca Alison Meyer

If you’re interested in other writing by Eric, including his O’Reilly and New Riders books about CSS, you could always check out his Writing page.