For what is used and what technologies are related to /#!/ in some websites URL's

Question

Possible Duplicate:
What's the shebang/hashbang (#!) in Facebook and new Twitter URLs for?

I'm curious about for what the expression /#!/ is used in some websites like Twitter or about.me.

Some examples: http://twitter.com/#!/search/programmer http://about.me/search/#!/tag/programmer

I like to know if there are specific technologies for using that, like a framework or programming language.

Answer 1

#! is called hashbang.

By reading Gawker Learns the Hard Way Why ‘Hash-Bang’ URLs are Evil and especially following the links for more technical-oriented information, you'll learn about one side of the story, the problematic one :)

SO: What's the shebang/hashbang (#!) in Facebook and new Twitter URLs for? seems to be the most voted question on the subject around here.