I'm trying to find an example to show where data is sent from a server and is pushed to a/multiple clients which are updated immediately, i.e. the client doesn't make requests for updates. It doesn't matter whether we're talking mobile, desktop or whatever. An even better example would be where there were multiple recipients for the same message. It doesn't matter what the data is or the context it's used in, only the immediacy of receiving it. I was thinking that there might be some example in finance and the stock markets, but I haven't been able to find any through googling.

IM clients are a great example of this and are on my list of one ;)

If anyone works on applications of this nature or knows of particular implementations, can you give me a quick run down of the use case and if it's commercial software the name of the software.

This is all basically for research purposes so doesn't have to be particularly detailed.

If anyone can help, thanks.