Today W3C announces a new version of a standard for representing knowledge on the Web. OWL 2, part of W3C’s Semantic Web toolkit, allows people to capture their knowledge about a particular domain (say, energy or medicine) and then use tools to manage information, search through it, and learn more from it. As an open standard based on Web technology, OWL 2 lowers the cost of merging knowledge from multiple domains. More than a dozen implementations of OWL 2 are already available. The standard consists of 13 documents, of which 4 are instructional.