.ORG (from ‘organization’) is one of the original top-level domains established in 1985. Operated by the Public Interest Registry (PIR), .ORG is popular among both commercial and noncommercial organizations, including community groups, sports teams, cultural institutions, and open source software projects. There are no restrictions on who can register a .ORG domain.
Why register .ORG?
.ORG is the third-largest gTLD, with over 8.5 million registered names as of August 2010. .ORG domains are recognized worldwide as the domain extension of choice for nonprofits, foundations, philanthropic and cultural institutions, religious, civic, arts, social and fraternal organizations, health and legal services, clubs and community volunteer groups. People expect to find these types of organizations at a .ORG domain.