Compatibility Between VB6 and VB .NET
Experienced users of Visual Basic 6 will find that once they understand key differences between VB6 and VB .NET, it's possible to easily migrate VB6 code to the VB .NET environment.
The Microsoft.VisualBasic compatibility namespace includes elements relevant to VB6 compatibility. If you open a VB6 project in VB .NET, the migration wizard will run. Migrating code from VB6 to VB .NET uses things from the compatibility namespace. For new code, I would suggest you use the new types, idioms, collections, and other features of VB .NET because elements of the Microsoft.VisualBasic compatibility namespace will probably find their way into the circular file soon.
Programming Elements Not in Visual Basic .NET
Many elements of VB6 didn't make it into VB .NET. Some aspects of VB6 were replaced and others are no longer supported. To provide you with a comprehensive table of VB6 elements, the elements that were left out of VB .NET are described in a table in Appendix A.Refer to Appendix A for a complete list of features that were revised or removed in VB .NET. (Many are covered in this chapter, but the table in Appendix A will provide you with one location for reference.)