http://www.lokasoft.nl/uk/jchess/chessgame.htm
There are a number of chess softwares which you can download.
I have tried playing chess online as well.
But how about integrating the chess applet into your own website?
Follow the simple instructions and you can allow your visitors to play chess onine!
http://www.shantanuoak.com/chess.htm

I have tested some of bulletin board services. Here is the final result.

Remotely hosted
http://amazingforums.com (Free Service)
http://www.ipshosting.com/?forumhosting ($45 for 6 months)
http://www.infopop.com/products/ubbx/free_ubb.html ($21 per month)
http://s2.invisionfree.com/shantanuo/index.php (free)
http://shantanuo.proboards22.com (free)

installation required
http://www.phpbb.com (Free)
http://phorum.org (Free)
http://xeoman.de/code/php/xeobook/index.php (Free guestbook)
http://www.vbulletin.com ($85 per year)
http://www.punbb.org (free)

If your company has IT Department that includes programmers, look into the "installation required" section. You will need a server with PHP and MySQL. You should also know how to install and configure the package.

"Remotely hosted" means the discussions will be hosted by the third party (for e.g. your mail is hosted on Yahoo!). The question of reliability is important here. If the server shuts down, you will loose all your discussions archives. You can see a working demo here..
http://amazingforums.com/forum1/SHANTANUO/