The .ORG domain was created by ICANN's on January 1, 1985. .ORG is one of the first and most respected top-level domains. Due to its brevity, the zone became very popular among nonprofit organizations, charity projects and open source-developers.
For non-profit organizations
Collect donations, organize charitable events and provide grants via your website registered with a .ORG domain name.
For opensource developers
Giving is a very rewarding thing to do. And you can give when you write programs and distribute them under free licenses on your site registered with a .ORG domain.
For student groups and projects
A group is also considered an organization, and representing your group with a .ORG domain name will further bring you people together as unit since you will be able to communicate better and more effectively online and everyone’s opinion will be heard.