Quat

Quat may refer to:

Quaternary ammonium cation, a class of chemical molecules
Quaternion, a non-commutative extension of the complex numbers
Khat, an African plant whose leaves are chewed as a stimulant
Phan Huy Quat, former prime minister of South Vietnam
[http://freshmeat.net/projects/quat/ Quat] an open source quaternion formula displayer