NCC Members have free access to this Guideline on the Principia website.

While the dot com bubble has well and truly burst, web technologies haven't gone away. In fact, more and more organisations are using them to add business value both internally and externally.

Generally a web application is seen as an externally facing transactional service that is accessed through a web browser. However, in practice this means anything from a simple online catalogue service to an online banking service that duplicates the functionality of a standard branch. The content management architectures used to deliver a modern informational site like BP.com make it possible to describe it as another form of web application.

Inside the business the corporate intranet is slowly changing into the enterprise portal. Here a web application is used to deliver personalised information to users, as well as acting as a gateway into a web-front-ended line of business applications. Acting as a single point of call, the enterprise portal is an important driver for the development of web applications within the framework of a modern business.

While some will describe web application development as a whole new paradigm, liberally scattering buzzwords throughout a presentation, in practice web application development is very similar to traditional application development. The key difference lies in the architectural approaches used. It's very difficult to put a web-front-end on a traditional monolithic application or even a client-server solution. Instead of the standard single user interface, a web application needs to work through a set of pages hosted in a browser.

This approach tends to lead to applications that are developed as a set of communicating components. Using web pages as the sources of application events, and as the place where results are displayed, web applications collect together these components into applications that closely resemble the three tier model: separating presentation from business logic and data.