(06-13-2010, 10:41 AM)Μαύρο Wrote: Why don't forums use AJAX to keep a synchronised update of current new posts? I've always wondered why

Because most software was created when AJAX wasn't as popular, and they haven't rewrote it.

You have to remember that AJAX makes server calls, meaning it's going to be pinging your server (basically) waiting for a response. If it's doing that every X seconds, and you have like 10-15 users browsing a thread it can become intensive.

Although a modification was released for vBulletin forums called Live Topic that uses AJAX to update a thread automatically.