I am really curious to know how Google Buzz and Facebook implement their comment feature which is being updated instantly. is it similar to Google wave technology? are there any resources to learn that technology and implement it to our website?
Thanks !!
I work on the Google Buzz team, so hopefully I can give you a good answer for our side of the equation. I obviously won't go into any of the confidential backend stuff, but I'm happy to address the open standards we use and the open source projects involved.
Starting in the UI space, we use technologies like Closure and GWT to build rich, responsive user interfaces. We use a technology vaguely similar to what you see in the Google App Engine Channel API to push real-time updates to the users. GAE is a really good choice for real-time web applications right now.
On the API side of things, we try to use open standards wherever possible. We use the Atom syndication format to enable feed readers to consume Buzz content, and Pubsubhubbub to enable real-time pushes of the content. In fact, we use Pubsubhubbub for our activity firehose — it's possible to subscribe to the entire real-time stream of all updates that happen in Buzz. Needless to say, this sends a massive amount of traffic to your application. On the JSON side of the equation, we use Activity Streams, and we're actively working with the community to refine and improve that specification. Our Atom feeds include Activity Streams as well, but the focus there is on syndication. All our secured API endpoints for Buzz use the OAuth standard for authorization.
On the backend, I think the only thing we're willing to say publicly is that Protocol Buffers are pretty awesome.