I'm trying to find an example to show where data is sent from somewhere, whether manually or automatically, and is received IMMEDIATELY by the recipient, (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 I think I'm basically looking for examples of applications that communicate over sockets.

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.