Visual Basic	Visual C++	Visual J++	VBA	Internet Explorer
	Licensing	Automatic support	Automatic support	Automatic support	Not supported	Extra work required
	Apartment-Model Threading	Required for multithreaded projects	Not required	Required	Not required	Not required, but needed for optimal performance
	Validate for LostFocus	Automatic support	Need to add an event	Need to add an event	Need to add an event	Need to add an event
	Mark Controls as Safe	NA	NA	NA	NA	Needed for medium or high security settings
	Parameters Passed By Reference in Events	Supported	Supported	Supported	Supported	Not supported
	Full Range of Variant Data Types	Supported	Supported	Supported	Excel supports only specific types	Supported
	Package Controls for Internet/Intranet	NA	NA	NA	NA	Extra work needed

Table 1 How Do They Differ? Let Me Count the Ways... No two environments (containers) that host ActiveX controls are exactly the same, but you can use VB to write controls that will function effectively in whatever containers you need to host your control in. This requires that you first understand the differences between various containers. If you intend to develop a control for all containers, you must ensure your control supports all the requirements of the container with the most stringent needs.