Open class

Open class may refer to:


 * Open class (linguistics), a word class readily accepting new items
 * Open (sport)
 * Open class (track and field), an event classification
 * Open 60 Class, a type of monohull sailboat
 * FAI Open Class, a glider competition class with unlimited wingspan
 * Open class (computer programming), the ability to extend already-defined classes
 * IBM Open Class (IOC), a C++ class library
 * Open class system, a state of society