Instant Messaging has exploded into the online world and is a wildly popular service of the largest Internet Service Providers (ISP) like AOL with AOL Instant Messenger, MSN with Microsoft Messenger, and Yahoo with Yahoo Messenger. Millions of Internet users everyday exchange IM s and its use beyond messaging is just around the corner. For example, the new Microsoft .NET platform will be using instant messaging technology for data exchange. This intermediate Java programming book provides Java programmers with the information and tools needed to create your own IM client and server software. You can use the software to create your own IM systems or integrate IM features into your existing software. Imagine allowing your customers to chat directly with technical support or other users from within your application! This book focuses on the open source Jabber XML-based IM protocols (www.jabber.org) to create Java IM software. These open protocols allows your IM software to seamlessly communicate with the large number of other Jabber clients and servers available including commercial Jabber systems like the one that powers Disney's go.com IM. Readers are assumed to know how to program in Java. No prior knowledge of Jabber or IM is needed.