I am incredibly impressed with this dude’s ability to rhyme about web standards. Not that his rhyming skills are hot, mind you, but the subject matter isn’t exactly the stuff of legendary hip-hop.

Validator S.A.C. is a Mac-only, stand-alone version of the W3C Markup Validator. With it, you can check the validity of HTML, XHTML, SMIL and MathML documents right from your desktop. Or you can run the validator as a web service on your Mac, which makes it available to other Macs on your network via Bonjour, and to other computers via IP. Plus you can run Validator S.A.C. from the disk image, or from a USB drive without installing.

The interface is nearly as easy to use as the online W3C validator. Enter a file’s location — either directly in the form field, or by selecting File > Open from the menu bar (or Command + O) — and click “Check” to validate — no Internet connection necessary.