Microsoft Web Control SDK

Microsoft is defining a new class of ActiveX controls called design-time ActiveX controls that are used exclusively at design-time (authoring time) to author web content. They function just like an embedded wizard that can be continuously edited to modify the text it generates into the web page. Design-time controls take advantage of all the rich OLE design-time capabilities – in-place editing, property sheets, and persistence – to capture user inputs, thereby extending the capabilities of any editor that supports design-time ActiveX controls.