“Rich” Web Clients

I am a keen advocate for “Rich” internet clients. By “Rich” I do not mean Java Applets, but web pages that provide a more complete user experience without having to request new pages from the server whenever the user clicks a button or link. There are few different approaches that provide this type of functionality including XUL (Mozilla Platform), Macromedia Flex and traditional JavaScript and DOM. Many web developers do not exploit the powerful capabilities provided with JavaScript and DOM. A recent example of this type of “Rich” client is Google's new Gmail capability that uses JavaScript and DOM to create a very quick and snappy user interface. By using JavaScript Google has been able to only send the basic requests and data transfers rather sending whole page changes back to the client. This of course takes quite a lot more client-side JavaScript development but does create a very powerful user interface. If you are interested in more information about the Gmail Agent API have a look here.

The Mozilla Platform is a more developer friendly approach as you define your application's interface in XUL and then link it together with JavaScript. However this approach requires your users to use a Mozilla-based browser (Mozilla or Firefox).

For the most interactive “Rich” client experience that will work on any browser Macromedia Flex is your product. Flex is based around a similar concept of Mozilla by defining your interface using XML documents and then linking it together with a scripting languages (Macromedia ActionScript). The difference is that Flex's client is built inside the Macromedia Flash player (available on almost every platform and browser), which allows for highly dynamic and pretty user interfaces. Flex is deployed using a J2EE server and can communicate back to the server by making Web Service calls or exchanging Java objects.

Gmail's approach works on all browsers but is technically much harder to implement. Mozilla's approach works well but requires a Mozilla-based browser. Macromedia's approach provides the best of both worlds but is not free and requires extensive server support. So if you are a web application developer please consider one of these options and provide a more advanced experience for your users.

Links
Mozilla Web Site
Firefox Site
Gmail Agent API Article
Macromedia Flex Site