The notion of online communities is a fascinating new concept that has emerged in this era itself. Online communities are the base of all the emerging ways of socializing on the web and depending upon their type, these are categorized into many forums like Social Networking Sites, Presence Services, Gaming Communities, Technology Discussion Communities and Forums etc. These are mostly used concurrently by people to stay connected in different ways to people they care about the most.

Twitter is one such online community which takes the form of a presence service. A presence service basically is one which provides the status information of a person at a given point of time to a list of authorized people, on multiple devices including computers, mobiles and PDAs, music players, Kiosks etc. In other words, or more correctly in the words of developers of Twitter:

“Twitter is a service for friends, family, and co–workers to communicate and stay connected through the exchange of quick, frequent answers to one simple question: What are you doing?” basically gives a user, the ability to provide their one or two line status information to their friends and families so that they can always know when the person is available and when not. This is similar to the concept that some phone companies including Nokia came out with few years ago in their phones and named it “Presence”. This service was basically based on GPRS based short text notifications sent to a server where it is stored and all users connect to it to share this status information. Twitter users also have the ability to send private messages to each other, much like in other communities like forums and gaming communities as well as in social networking sites like Orkut and Facebook.

The service of twitter is also available on almost all the phones that have GPRS enabled on them. Going one step further, most PDAs of today like Windows Mobile Based PDAs by HTC, O2 and XDA or Palm OS based systems from Palm Inc. and many others have specially crafted applications for these phones to make the task more enjoyable and functional on these devices. Other some devices that have the capabilities of providing Twitter services include music players such as iPod from apple, some kiosks etc.

All this multiplatform access is possible due the fact that Twitter uses a standard API (Application Programming Interface) for all the communications that are done with its servers. This API is based on HTTP, XML, SOAP (Simple Object Access Protocol) and REST based technologies which are established standards. So it becomes very easy for the developers to develop applications around it as almost all modern computer languages have support for these standards.