Few years ago only lazy didn’t say about bringing desktop application experience to the web ones. However in reality, it just meant that user actions didn’t always required page reload, but could change page UI dynamically. As for other application events, as a rule they were not handled dynamically. Well, now you can find more and more web applications acting really like desktop ones. For example, Facebook and G+ have widgets which update automatically.
Items in category real-time web
Apparently social networking is the banner of the nowadays web. Everybody intends bringing some features into his projects. Some of them require immediate notification. That is getting common, if you open a page with upcoming messages (status feed, notification subsystem, friends-list), you expected them being updated as soon as a new message (status, notification, friend-making action) arrives. As you well know, original web design allowed only one-way client-server communication (one requests, another one responds), though now HTML5 working group doing their best to fix it or rather to patch it.
Related articles: Bringing realtime to your web applications and WebSockets vs Server-Sent Events vs Long-polling Besides, already noted bidirectional communication channel, known as WebSocket, HTML5 propositions include also comet communication pattern by defining Server-Sent Events (SSE). WebSocket widely discussed by now, tons of server implementations are available and you can play already with fluent browser implementation under Chrome. However the second server-push technology of HTML5 yet stays in shadow. We are used to consider the HTTP protocol as request-response model, which means that the client sends a HTTP request and waits until the HTTP response is received.
RIAis considered as one of the mostly particular to the modern Web feature, and often stands for the trend, according to which web-applications tend to desktop applications. Nonetheless the approach is very relative. Overwhelming majority of “rich” web-applications is still built on the “request-response” model. I.e. events of the client side can be reflected on the sever side, but not vice-versa. In order to make such a trivial thing as a chat, you have to go with tricks.