Elgg is a very flexible and powerful OpenSource - Social Network. This PlugIn integrates a slightly modified version of PhpFreeChat (OpenSource too) in that environment. With v1.2.2 there are a lot of new options in the admin interface to customize your chat in the way you like.
You're able to customize your chat plugin via elgg's tool administration page. If that is not enough for your intention and you have to touch code, please keep following points in mind.
In order to avoid conflicts between jQuery and Prototype, the $-function had to be overwritten with a function named proto(), which provides the same functionality. Please keep this in mind when you install new phpfreechat themes that access to the $-function of prototype.
When you want to display the real name (not the username) in the chat, you could do that by changing the assignment to $params['nick'] in chat/pfc/index.php (by using name instead of username). However please note that the profile link in the buddy list won't work anymore.
Versioning
Since version 1.2 the version of Elgg and this plugin are synchronous. This means that the Chatplugin 1.x.y is the y-th release under Elgg 1.x.