WapcamServer can work with a lot of external 'clients' because it respects norms and international protocols.
Must VLC still be presented? A reference for a mutlimedia player. It reads RTSP/RTP streaming as well as MJPEG/HTTP.
Apple's media player offers interesting possibilities. It too reads RTSP/RTP streaming and MJPEG/HTTP, but it can also do progressive download, for exemple, when you download an mp3, the quicktime player opens up and begins to play the song directly. It integrates into Internet Explorer or Firefox.
Here is a list of softwares supposed not working with WapcamServer:
Windows Media Player
The great absent; it doesn't support either rtsp streaming, nor mjpeg. Not much to say then.