For Alpha Phi Omega (Community Service co-ed)
Harvard - Never
Princeton -Inactive
Yale - Inactive (within last year)
Cal Tech - Never
MIT -Active (First chapter in New England)
Stanford - Active (First chapter on the West Coast)
U Penn - Active
Colombia - Inactive
Chicago - Active
Duke - Active
Dartmouth -Never
Northwestern - Colony
Wash U - Active
Johns Hopkins - Active
Cornell - Active
Brown - Inactive
Emory - Active
Rice - Inactive
Vanderbilt - Active
Notre Dame - Inactive
Berkeley - Active
Carnegie Mellon - Active (my alma mater!)
Georgetown - Active
UCLA - Active
UVA - Active
15 Active
1 Colony (APO calls them Petitioning Groups)
6 Inactive
3 Never
The existence of Alpha Phi Omega definitely doesn't indicate one way or another whether there is an active Social Greek system though.