File with an .OCX extension contains information related to the standard control actions of objects called with user’s or system’s actions. These are files relating to objects within ActiveX forms, stored in programming languages such as C++ or Visual Basic. They used to be commonly referred to as the non-standard OLE controllers – Object Linking and Embedding, presently they are called the ActiveX controllers.

OCX files contain constituent objects of the Microsoft ActiveX technology. They can be utilised to describe actions such as changes of the size of program’s windows or bar scrolling. For instance, the mscomctl.OCX and comctl32.OCX of the MS Visual Basic 6.0 files contain updated common controllers of programs stored in this language. They are created in the integrated programming environment, for instance the Microsoft Visual Studio.