1. Twitter Yun Wu

2. What is twitter Twitter is a social networking site based around text messaging. First, you register yourself at www.twitter.com, then invite a few friends into your Twitter network as friends.

4. How does it work? With Twitter, you can stay hyper– connected to your friends and always know what they’re doing.

5. It is the text-based post of up to 140 bytes in length. Updates are displayed on the user's profile page and delivered to other users who have signed up to receive them. Senders can restrict delivery to those in their circle of friends (delivery to everyone being the default).

6. History(1) Twitter was founded by Jack Dorsey, Noah Glass, Biz Stone, and Evan Williams The public introduction began in March 2006 inside San Francisco podcasting company Odeo. The service rapidly gained popularity: In March 2007, it won the 2007 South by Southwest Web Award in the blog category

7. On April 22, 2008, Twitter announced on its blog that it had created a version of Twitter for Japanese users. One week after its launch it was reported that the Japanese version of Twitter had started gaining users; Japanese is now the second most-used language on Twitter

8. Architecture-difference between twitter and blog Blog and twitter have a lot in common, but the important distinction is size. A twitter update is 140 character maximum. A blog post can be hundreds of words, and it can include pictures, audio and video. A blog is a much more complicated thing but it can bring a lot more to your organization if you have the time and resources. Twitter is quick to start and quick to use.

9. Why use twitter-Use Twitter for good 1.Quick Human Answers: Ask folks on your friend’s list which digital camera to buy for under $300 US, and you’ll get back a stream of responses in a short time.

10. Why use twitter-Use Twitter for good 2.faster news spread: Twitter lead the media and the blogsphere in breaking news about US Airways flight 1549 crashing in New York's Hudson river. Twitter users broke the news of the incident around 15 minutes before the mainstream media alerted viewers and readers to the crash

11. How is Twitter built The engineer team works with a web application framework called Ruby on Rails. Ruby on Rails, is an open source web application framework for the Ruby programming language. It uses the Model-View-Controller (MVC) (MVC means the model represents the information (the data) of the application; the view corresponds to elements of the user interface such as text, checkbox items, and so forth; and the controller manages the communication of data and the business rules used to manipulate the data to and from the model.) architecture pattern to organize application programming.

12. Features of ruby on rails Ruby on Rails features several tools intended to make commonplace development tasks easier "out of the box". Rails provides scaffolding which can automatically construct some of the models and views needed for a basic website

13. Framework structure Ruby on Rails is separated into various packages, namely Active Record (an object-relational mapping system for database access), Active Resource (provides web services), Action Pack, Active Support and Action Mailer. Apart from standard packages, developers can make plug-in to extend existing packages. Apart from standard packages.