Web based Chat
Web based chat has been an issue that many sites have wanted for a long time. It used to be you had to have Java, a Sun Microsystems program to run any type of chat. The Java chat would require the Java client and a connection to an IRC channel/server for the chat to be utilized by people. Well not everyone had the Java client and if they did their browser may not support the version they are using. This caused a problem with a lot of web masters wanting a chat that will work for almost anyone without having to download any extra software.
Users Currently Online
AJAX is very versatile and powerful. In this sense we can show users currently online with little to no delay unlike before. When a user comes online we can send a signal to a file to retrieve the user information and display it on the page. This combined with session data and AJAX we can show users who are currently online. With a more in depth audit trail we can show more information about the user also if desired. Like the current web page they are viewing, how long they have been on the web page, and when they leave the page. Using this logic we can show when a user has logged off and update the current users online instead of having to time them out after a certain amount of time (usually 5 minutes). This can also be seen on Aeonity.com in the Web based chat area also.
Denver CO Blog