ZNC is an IRC bouncer with many advanced features such as a built-in web interface, persistent connection (detaching), multiple users, per channel playback buffer, SSL, IPv6, transparent DCC bouncing, and c++ module support, to name a few.
This project aims to distribute a easy and friendly chat that can be installed on any network. You can use it on every browser. The system uses AJAX and PHP.
Chatlet is an applet / servlet gateway to IRC. It makes it possible to transparently connect to IRC using a standard webbrowser, even if you are behind proxies and firewalls, as all communication is done via HTTP.