Hosted Chat or "Chat As Service" is an ASP (Application Service Provider) model text chat service that boasts capabilities such as having multiple instances of a chat with different configurations being distributed among websites, blogs, discussion groups, and virtually every other type of online community. Since it is an ASP model and is hosted, Hosted Chat / Chat As Service requires no software installation and the users always get the latest version of the service.
Commonly used Java chat interfaces include PJIRC and Chatspace.