While working on a streaming media project, I found Windows Media Licensing has lots items.
Streaming Media Server is part of Windows 2003 Server as free add-on. To encode streaming media files you can use Windows Media Encoder. Digital Rights Management (DRM) can be used to more protection of your media contents. There are many things to facilitate your streaming media.
I will cover streaming media later some time. For now see the below links on licensing of Windows Media technology.
Deciding Which Version Is Right for You
Windows Media Licensing Program