Robots.txt syntax checker

Writing robots.txt files is relatively straightforward. However, its still fairly common to get some small part of the syntax wrong, and then to find that a robot has wandered all over your site because of it.

This robots.txt syntax checker checks the contents of a site's robots.txt against that contained in the latest specification, along with providing warnings on the use of new features that are not yet widely deployed.

Its still in its early days, and I'd be very interested in any suggestions or comments about it. Let me know what you think!