.OCX File Extension

Object file used within ActiveX forms; contains control behaviors that typically are triggered by user or program events; may be used for functions such as window resizing and scroll bar movement handling; commonly written programming languages, such as Visual Basic or C++.

OCX files were originally called Object Linking and Embedding (OLE) custom controls, but now are referred to as ActiveX controls, which is the component object used in Microsoft's ActiveX technologies.

OCX files may be created by various software development programs, including Microsoft Visual Studio.