# Why are the ActiveX Control and Control Container Guidelines Important?

ActiveX Controls have become the primary architecture for developing programmable software components for use in a variety of different containers ranging from software development tools to end-user productivity tools. In order for a control to operate well in a variety of containers, the control must be able to assume some minimum level of functionality that it can rely on in all containers.

By following these guidelines, control and container developers make their controls and containers more reliable and interoperable, and ultimately, better and more usable components for building component-based solutions.

This appendix provides guidelines towards good interoperability. It is expected that new interfaces and component categories will develop over time, future versions of this appendix reflecting these changes will be made readily available through Microsoft. It is important to note that this appendix does not cover detailed semantics of the OLE interfaces; this is covered by the Win32 SDK documentation.