Gabe Weatherhead of Macdrifter and Eric Hess of The Mindful Bit have teamed up to develop a new syntax called CriticMarkup, which is useful for denoting editorial changes in a document and is fully compatible with Markdown, LaTeX, and HTML.

As someone who doesn't do a whole lot of collaborative writing, I honestly don't have much use for this currently, but I think it's a fantastic idea and something I'll be keeping on my radar.

They've come up with lots of other goodies to go along with the syntax, so head over to Gabe's site to read more about the project or visit the CriticMarkup site itself.