What is .NET?

To put it in the simplest of terms, .NET is Microsoft's initiative to deliver software as a service. Another way of looking at it is that the impact of .NET will be the following:

• For programmers: A paradigm shift in the approach to software development and deployment.

• For architectures: Internet processing power to be distributed more on the peripheral clients and less on the Web servers, enabling much better use of the Internet.

• For the future of the Internet: Ultimately, the Internet will become more an operating system and less just a means of connecting computers together.

These things are mostly about the future. What does .NET mean to programmers here and now? The first major change that you will see with .NET is that the medium for software delivery will change from full-functionality CD-ROM installations to much smaller, as-needed-functionality Internet downloads.

.NET provides the functionality to place small elements of your application programs on a Web server. These elements can then be downloaded on an as-needed basis, when that application is executing. Basically, applications run as described in these steps:

1. A user attempts to start an application using the .NET runtime.

2. The runtime checks to see if an up-to-date version of the application is in the system's cache. If it is, the runtime executes it from the cache; otherwise, the runtime downloads the updated version and then executes it.

3. While the application is running, it may require other elements. When one such element is required, the runtime checks the cache to see if it exists. Then, the runtime makes one further check to ensure the element is up-to-date. If there is no version in the cache, or it is not up-to-date, then the element is downloaded.

As you can see, this is considerably different from how it is done now, whereby everything is placed on a CD-ROM and installed at one time. I'm sure you can see that the .NET method ensures that the "latest and greatest" are always being executed.

Does this mean that the only way of distributing software is via the Internet? No, there is nothing stopping you from distributing the old way or even combining the two methods, where you install everything up front and then use the Internet to keep everything up-to-date.

As you can imagine, developers now have to start designing their software in a much more modular fashion. Developers also have to be conscious of what modules will likely go together so that those modules can be downloaded concurrently to mitigate the amount of time a user has to wait between running different functionalities of the application. This will also allow for more efficient usage of the Internet.

Another major aspect of .NET that developers will become quickly aware of is that applications are no longer restricted only to the computer on which they are running. It is now possible to execute code from Web services on computers anywhere around the world. True, with some complex DCOM, COM+, CORBA, and so on coding, you could, before .NET, escape the sandbox of the application host computer. But now with .NET, the code to access the resources of the Internet is effortless. Equally as easy, it is possible to make your resources available to the Internet. With .NET, a computer does not have to be an island.

Note

Wherever you read the word "Internet," you can assume "intranet" applies as well.