Encyclopedia Britannica has launched an online index to quality resources on the Internet (www.ebig.com). Unlike the online version of the encyclopedia itself, the service is currently free, leaving its 25 full-time editors and indexers with no obvious means of support. Tim Pethick, the executive overseeing the project, said that he would consider taking advertisements on the site - a move which would take Britannica into competition with Yahoo!, which became the Internet's biggest ad earner by helping people search the Web.