I've already said in a number of blog comments that I'm surprised at the number of companies who have licensed Microsoft's communications protocols.
Surprised that the number is so high, that is. Most of the protocols are only of use to anyone producing systems management software intended to replace the mechanisms already in Windows. Alternatively, you can obtain some of the extended authentication protocols used by Windows in dial-up networking and network file systems. There are some details on remote procedure calling and implementing the DCOM protocol. You get the idea.
Very little of this is of any use to the typical ISV. We are, for the most part, interested only in using these services, not reimplementing them.
The prevailing attitude among systems companies such as IBM is to use Open Source software to provide interoperation with Windows platforms, such as Samba. Open Source is incompatible with the licence terms of the Communications Protocol Program - the licensee is only allowed to disclose source code on their own premises, subject to some confidentiality clauses. Otherwise, systems companies are only interested in making Microsoft follow their standard, not vice versa. No other operating system has ever implemented COM, disregarding a Microsoft-sponsored port to Solaris.