The chat system is based on a Java web server and is accessible by the user via a regular web browser (http). The messages written by a participant are forwarded to all chat participants. The HTTP protocol is state-less, that means it isn’t able to recognize which participant already received a message.

Through the Pushlet technology the participant is informed about new messages in the chat, without having to send requests all the time. HTTP streaming is the foundation for that technology. The Pushlet creates a permanent HTTP connection. This is realized through an infinite loop which exchanges packets between client and server. This keeps the connection open all the time.
Pushlets don't transmit HTML code, but JavaScript elements, which enables them to create dynamical changes in a static HTML site. This technique is also called Dynamic HTML (DHTML) or AJAX.