Markdown is a text-to-HTML conversion tool for web writers. Markdown allows you to write using an easy-to-read, easy-to-write plain text format, then convert it to structurally valid HTML. Markdown can be learned in a matter of minutes, as you write your content, or you can use a Markdown editor for visual formatting.
A complete guide to Markdown syntax may be found on John Gruber's Markdown page.
Free Markdown editors are also available for download. Use them to write and style your content, then copy-and-paste into Lightroom:
The Turning Gate
Creating webbly, wobbly, Lightroomy things since 2007.