I am curious about COM+, DCOM. I know that MSFT does not encourage you to use this tools natively (meaning with C/C++, in fact there is not a lot of documentation available)
Actually, if you want to learn more about COM, Microsoft publishes a book about COM and how it works... http://www.amazon.com/Inside-Microsoft-Programming-Dale-Rogerson/dp/1572313498/ref=sr_1_2?ie=UTF8&s=books&qid=1243029018&sr=8-2