JChess is jQuery and PHP based multi player chess
Here's how you can see it in action: Open http://haisum.info/chess/ in chrome and another window in firefox or incognito mode in chrome so that you can log in with two different users. I made two users haisum1 and haisum2 both having password qwerty.
Unfortunately this code isn't secure, I wrote it in university days and didn't care much about security. I am not hosting it anymore for demo, you can download and play around with it on your local system.
Log in into app from two different browsers abd with different users and invite for game :) You can then move your pieces or drag and drop them. Don't use IE it has many issues in IE and sorry for weird messages and alerts it was a hobby project so left them unfixed :) hope you will like it.