MesSerChat 3.1 (For DotNetNuke 4.5, 4.6, 4.7, 4.8 and above)
Take advantage of the Microsoft® AJAX Library and the ASP.NET 2.0 AJAX Extensions.
Built using the extended set of object-oriented capabilities provided by the Microsoft AJAX client library.
Use JSON, a lightweight data-interchange format, for client-server communication.
Low CPU, bandwidth and Memory usage.
More security, more stability, more usability.
Includes features such as font size,font color customization, emoticons, sound notification, private messaging, ignoring users, cross-browser compatyibility.
Live demo chat
http://www.snowcovered.com/Snowcovered2/Default.aspx?tabid=242&PackageID=9465