There is now an updated version of the chat package in CVS oacs-5-2. It uses either ajax-chat (based of the stuff that i have develoed for xowiki-chat, now moved to xotcl-core) or alternatively the java-chat (depending on a parameter). Peter Alberer did the integration and implemented the list of active users. Earlier versions had some troubles with Safari, but now the major browsers seems to work well. As a new feature, it uses now different colors for displaying users.
If you use it, please get as well a fresh copy of xotcl-core from CVS head.