Pipes In GUI's

Caine asks: "While having some dead time at work, I spent some time thinking about how to write a good GUI. I started thinking about if you could implement pipes in a GUI. My thought was something like this: You could connect two programs and/or widgets by a GUI pipe. This could be visualized if the user wanted to, as a thin, pulsating red line or something. For example, you could pipe your browsers' status/error window to a log colorer. You could also pipe other things than text, such as pictures; if you're watching a streaming movie you could pipe it into the graphic programs' filters for example. Basically they would do the same as a normal "|" but with all kinds of data and in a GUI. Has this ever been done or written about before? Any implementations?" Interesting idea, but before this would be possible, we'd have to introduce the concept of discrete input-channels and output-channels into our GUIs, and that's not as easy as it sounds.