Sockets are very new. Way back when, you'd either use COMET, which was a connection that the server wouldn't close, and you'd append data to it, for the js in the browser to use. This was one directional, so going the other way still required separate requests

For real bidirectional sockets, it was common to make or use a small flash file. You'd talk to it with js, and it would handle the actual socket stuff. Worked pretty well