Ajax is based on open standards, which makes it work well across many browsers. It is cross-browser and cross-platform compatible. It’s possible to build Ajax-based rich Internet applications on most modern browsers. People like having options, so not being limited to using a certain type of browser is a very important thing for a developer. By being based on standards that many people are familiar with already, the learning curve to transition to building rich Ajax applications is not that big. Ajax also works well when it is combined with Flash.
Ajax helps to improve usability. It provides a better experience for the user. It feels as if any changes that happen are instantaneous. Good user interfaces make things get done quicker. In this information-rich age, efficiency is key.
Many successful websites currently use Ajax technology. Google Maps is a considered one of the most impressive ones. Other popular services from Google, such as Gmail, Reader, Suggest also use Ajax. In Gmail, Ajax takes care of spell-check, auto save and checking for new emails, among other things. Flickr uses Ajax too, and so does Meebo, a popular web-based IM client.
Some things that Ajax could be used for are browser-based chat applications or instantaneous form validation – done while user is typing. It could be used for smooth navigation, contracting and expanding them without the need to load a new page.
Ajax is mobile-friendly. Pocket PCs and smartphones support it. It can be easily predicted that Ajax will play a key role in enhancing mobile user experience.
In the end, Ajax sounds like a very useful thing to know. It is very powerful, as evidenced by the success and popularity of Google Maps, Facebook, Gmail, etc. By being based on technologies that are already sort of familiar to people, it encourages people to learn it. Trying to program something in Ajax isn’t going to feel like learning a completely foreign language. That, combined with how much can be done using with, makes people excited about working with it.