Which is "better": COM DLL or standard DLL with Typelib?

Question

I put “better” in quotation marks because this is a quality issue. I have been writing COM DLLs for a couple of years and recently applied a standard DLL with the Typelib concept and successfully use it.

Are there any good reasons to use COM DLL instead of DLL + Typelib? Of course, you cannot do DCOM with DLL + Typelib, but is this the only reason?

EDIT I wrote COM DLLs in Visual C / C ++ 6, Compaq Visual Fortran, Delphi, Visual BASIC 6, ActiveState Perl and some others. I wrote standard DLLs in Visual C / C ++ 6, Delphi, Ada and some others. I wrote typelibs for some of my own standard DLLs, as well as third-party DLLs. The question was originally written in the context of the Delphi DLL + Typelib implementation for the original VB6.

Answer 1

TypeLib is also important if you ever want to port COM components to managed code in the future. Or managed code interacts with COM components.

There are many tools with typelib that automatically convert your COM signatures to .Net interfaces and types. This can be done manually, but with a large project it is certainly a huge time saver.

Answer 2

It really depends on the client component that I would think.