How does one achieve realtime messaging between different instances of (perhaps different) PHP scripts?
<p>I'm working on feeding the client realtime events using event-streams and HTML5 SSEs client-side.</p>

<p>But some of my events will actually come from form submissions by other clients.</p>

<p>What's the best method for detecting these form submissions (so as to append them to the event-stream script) ASAP (after they occur)?</p>

<p>So essentially, I need realtime cross-script messaging between multiple instances of different scripts instantiated by different clients, analagous to X-doc messaging in JS, but for PHP.</p>

<p>The best I can come up with is to repeatedly poll a subdir of <code>/tmp</code> for notification files, which is a terrible solution.</p>
