One of the hottest new web development techniques around today is AJAX (Asynchronous JavaScript and XML). AJAX allows you to create interactive web applications by using a combination of JavaScript, XML and XHTML, which makes web pages feel faster because some of the data is exchanged with the server throughout the session instead of every time a page is reloaded by a user. The overall goal and purpose of AJAX is to create an interactive experience for the end user while increasing the speed and ease of use.

Pros:

• The User Experience – The number one advantage of using AJAX programming is the new and fresh interface it provides users. Users relate their experience with AJAX web pages to be more like a separate application than a standard web page. When someone clicks on a link on an AJAX web page, the page can usually be updated dynamically as opposed to a standard web page where the entire page is refreshed and it seems like a big operation. This greatly reduces the amount of click and wait time a user will experience. As people are using the Internet more and more, user interface is making a huge factor in what people do with their time online. The more attractive and easy to use a web site is, the more likely the user will return to your site.
• Flexibility and Accessibility – So many people are now using more than their home computer. Internet users access their online information from home, work, school and a variety of other places. With the use of AJAX and online applications, Internet users can access their data online from a web application. This eliminates the need to carry around expensive hardware from place to place. You can virtually access your data anywhere you can connect to the Internet. Online applications using AJAX also eliminate the need to update your software regularly. The software can be updated on the server side and display the most recent build of any program to the entire public.
• Low Bandwidth Usage – AJAX limits the calls to the server by generating the HTML within the user’s browser. Most of the requests to the browser are just for JavaScript and actual data. Since there is less data coming from the server, an AJAX web page seems to load much quicker.
• Different Platforms – With the use of AJAX and online applications, the variety of platforms out there has less of an impact on both the users and developers. Programmers won’t have to develop their software for all the different platforms available. For the users, you don’t have to worry about PC , Mac or even the up and coming Linux.
• AJAX is coming – The total impact of AJAX has yet to be seen but it is already being implemented by large corporations which is a good sign that there is still more to come. The Internet giant, Google, is already using AJAX for some of their projects including Google Maps and Gmail. AJAX meshes perfectly with the new “Web 2.0” user interaction idea; making it a strong candidate for further use.

Cons:

• Changes to the End User – AJAX technology will include small but important changes to the way an Internet user uses their browser. An AJAX page will not register itself with the browser history engine so when the user hits the back button (a very common function that everyone uses) it will not render any changes. Also, the bookmark function which is very popular among Internet users will not have the same effect as it used to. These may seem like small, insignificant changes but many users take advantage of these features daily. For some users, small changes may not be a big deal but to less experienced users who have a hard time learning new technology; this could play a big role.
• Still using JavaScript – One of the key components of AJAX is the use of JavaScript. JavaScript is a great code that features awesome interaction to users but has its own sets of con’s. JavaScript is not very friendly to search engines as the text and information within them is not visible. The other issue with JavaScript is it’s compatibility with other browsers. JavaScript information may be displayed differently between Mozilla Firefox and Internet Explorer.
• Search Engine Optimization – As discusses briefly in the previous Con, AJAX web pages may not be visible to the search engine’s bot that crawls the web to index different web sites. Not having your web site in the top search engine’s index can result in a quick death to your site if it depends on Internet traffic. There are techniques to avoid this issue but it will require further time and programming.
• Internet Access – With online web applications and AJAX, you obviously have to be connected to the Internet to use these. Lots of people have constant access to a bandwidth Internet connection but not everyone is able to connect at high speeds anytime which would mean that this would be a serious con for those users.

As with any new technology, AJAX has its advantages and disadvantages but with the pros mostly outweighing the cons and huge companies like Google already using AJAX, you can expect to see more and more AJAX web sites out there in the very near future.

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