Not sure what you mean by non-greek. fraternities and sorrorities are only greek in name. There are non social fraternities and sororities that have a more academic or leadership focus...a few examples are Gamma Sigma Alpha (academic), Phi Beta Kappa (academic), Rho Lambda (leadership)... non social but technically still greek.
Nearly all colleges and universities have fraternities and sororities.
Yes, graduate students can join fraternities at some universities, but it varies depending on the specific fraternity and university policies.
In fraternities and sororities.
Greek Gear mainly produces clothing and other accessories for sororities and fraternities. There are other non-specific clothing that incorporates some type of Greek themes outside of collegiate alumni.
Anyone who isn't Greek.
Greek
yes there is a greek system at Purdue
Howard
because of the hazing. Some students died because of hazing.
Oh yeah. Big Greek life at FSU
Yes, though in Europe they are not called Fraternities and Sororities, instead they are called Nations and Verbindungen.
No. It does not have fraternities or sororities.