How about embedding of a Windows Media Player control on a Form? See
http://msdn.microsoft.com/en-us/library/bb383953%28v=vs.90%29.aspx[
^].
[EDIT]
Clarification based on a comment by OP:
Please see the answer to this comment. The question was about client side only, and embedding the player is all which is required. Everything else can be done on server-side only. Some cameras implement streaming protocol on hardware level. Normally, you do it in server-side software. Here is one idea: you can see how it's done from the source code of VideoLAN, see:
http://en.wikipedia.org/wiki/VideoLAN[
^],
http://www.videolan.org/vlc/download-sources.html[
^].
Are you sure you really need to write your own code? You can directly use VLC (see the references above) to stream almost anything almost anywhere. You can get this product for nearly all platforms.
—SA