About 65,000 people have become LEED Accredited Professionals (LEED APs) since the program began in 2000 as a way to recognize experts in the U.S. Green Building Council’s (USGBC’s) LEED Rating System. In November 2008 at the Greenbuild conference, the Green Building Certification Institute (GBCI), the organization that administers the LEED AP credential, announced substantial revisions to the program.