htmlPlayground is a helpful reference for web developers of any skill level. It provides an easy way to generate, test, and learn about HTML and CSS syntax. Simply select your reference (HTML tags, attributes, or CSS properties), and then select an item like "blockquote."

htmlPlayground will then display a description of the item (to explain what it's used for), an example code snippet that is editable, and a rendered preview of the code snippet. The snippet is color coded: green for tags, red for attributes, and black for regular text.

If you click on a green tag in the snippet, you can edit the tag's attributes easily via another pane. When you're happy with your finalized code, you can of course copy/paste it to an HTML file to use on your website.

[Via garyll]