it isn't so much a program as it is technology and APIs. There are several ways to accomplish this. If you are using HTML5 you could use Cross Document Messaging or ChannelMessaging. Cross Document Messaging is a one way communication between two different domains. ChannelMessaging is a two way asynchronous messaging between two browser windows that uses ports to attach to the window. However these also have protection in place so that these processes only run in their own sandboxes
Also in HTML5 is SSE or Server-Sent-Events or WebWorkers. These both allow for asynchronous communication between a client and host computer. Both of these could be used to initiate communication between computers using peer to peer communication. You could also use TCP/IP or Telnet. Actually Telnet can be use to control remote servers and Telnet uses the underlying TCP/IP protocol which in turn uses an IP address.
For instance you could enable the Telnet client in Windows by accessing the Windows features trough the control panel and "Turn On or Off Windows Features". Select the Telnet client. Then from the "Run" prompt type services.msc to bring up the Windows services. Locate the Telnet service, right click on it and click on "Start"
Once the service is finish loading, open a commend prompt by typing in the "cmd" command un the "run" prompt under the Start button.
Type telnet followed by the IP address like: telnet 000.000.000.000. To get the IP of a web site, simply write ping and the domain name like ping www.hubpages.com. Of course this is all theoretical because most web sites are protected by firewalls and proxy servers (its not like in the movies). However you could with the proper permissions to access a remote computer and then use a software to stream your data.
Data streaming can be accomplished using a variety of APIs available in most programming languages like Java, Objective-C or C# or yet again PHP. You write a web service which could send and receive data streams. In Java you could write a servlet that uses the HTTPRequest and HTTPResponse methods. In C# you could also create HTTPhandler (ashx file) to receive and send HTTP responses.
So in essence, there are many ways to stream data from one computer to another if you have the proper permissions or if the system is configured to allow such as thing over the Internet.