W3C Feed Validation Service.

W3C has compiled this list of questions to help public and W3C Members alike understand the future development of XHTML in the W3C.

an open, XML-based protocol originally aimed at near-real-time, extensible instant messaging (IM) and presence information (e.g., buddy lists), but now expanded into the broader realm of message oriented middleware.

url inclusion protocol. from wikipedia.

from Google's Webmaster Tools.

structured data coupled with capable display primitives. from sitepoint.

the topic of extensible markup languages.

turning xml into a usable format for programming.

where we're one step closer to the semantic web.

transform your microformatted content to nice, clean, easily digestible xml or json.