Getting Started with ASP.NET

What is ASP.NET?

ASP.NET is a server-side framework for developing Web applications based on the Microsoft .NET Framework. Coming to grips with that lingo-filled description is the first challenge faced by any developer who wants to build dynamic Web pages with Microsoft technologies today. In this section, I'll try to break down the jargon to give you a clear picture of exactly what ASP.NET is and what it can do for you.

ASP.NET is server-side; that is, it runs on the Web server. Most Web designers start out by learning client-side technologies like HTML, JavaScript, and Cascading Style Sheets (CSS). When a Web browser requests a Web page created with client-side technologies, the Web server simply grabs the files that the browser (the client) requests and sends them down the line. The client is entirely responsible for reading the code in the files and interpreting it to display the page on the screen.

Server-side technologies like ASP.NET are different. Instead of being interpreted by the client, server-side code (e.g. the code in an ASP.NET page) is interpreted by the Web server. In the case of ASP.NET, the code in the page is read by the server and used to dynamically generate standard HTML/JavaScript/CSS that is then sent to the browser. Since all processing of ASP.NET code happens on the server, it's called a server-side technology.

ASP.NET is a framework for developing Web applications. A Web application is just a fancy name for a dynamic Web site. Web applications usually (but not always) store information in a database on the Web server, and allow visitors to the site to access and change that information. Many different programming languages exist for creating Web applications: PHP, Java, Perl and Cold Fusion are just a few of the more popular ones. Rather than tying you to a specific language, however, ASP.NET is a framework -- a technology that lets you write Web applications in your favourite (supported) programming language.

And finally, ASP.NET is based on the Microsoft .NET Framework. The .NET Framework collects all the technologies needed for building Windows applications, Web applications, and Web services into a single package with a set of twenty-some programming languages. To develop Web sites with ASP.NET, you'll need to download the .NET Framework Software Development Kit, which I'll guide you through in the next section.

Ok, so with all the jargon demystified, you're probably still wondering: what makes ASP.NET so good? Compared to other options for building Web applications, ASP.NET has the following advantages:

• ASP.NET lets you use your favourite programming language, or at least something that's really close to it. The .NET Framework currently supports over 20 languages, all of which may be used to build ASP.NET Web sites.
• ASP.NET pages are compiled, not interpreted. Instead of reading and interpreting your code every time a dynamic page is requested, ASP.NET compiles dynamic pages into efficient binary files that the server can execute very quickly. This represents a big jump in performance compared to interpreted languages like PHP, Perl, and ASP.
• ASP.NET has full access to the functionality of the .NET Framework. Support for XML, Web Services, database interaction, email, regular expressions, and many other technologies is built right into .NET, which saves you from having to reinvent the wheel.
• ASP.NET lets you separate the server-side code in your pages from the HTML layout. When working in a team composed of programmers and design specialists, this separation is a great help, as it lets programmers modify the server-side code without stepping on the designers' carefully-crafted HTML and vice versa.

With all this going for it, ASP.NET has relatively few downsides. In fact, only two come to mind:

• ASP.NET is a Microsoft technology. While this isn't a problem in and of itself, it does mean that (at least for now) you need to use a Windows server to run an ASP.NET Web site. If your organization uses Linux or some other operating system for its Web servers, you're out of luck.
• Serious ASP.NET development requires an understanding of object-oriented programming. If you don't consider yourself a programmer and JavaScript gives you a headache, ASP.NET is probably not the best choice for you.

Still with me? Great! Time to gather the tools of the trade...

What do I need?

For the moment, if you're going to learn ASP.NET, you're going to need a Windows-based Web server. Open source initiatives are underway to produce versions of ASP.NET that will run on other operating systems, such as Linux; however, these are not expected to be available in stable form for at least several months.

While developers had the option of getting their feet wet with ASP on Windows 95, 98, or ME using a scaled-down version of IIS called a Personal Web Server (PWS), ASP.NET requires the real deal. As a bare minimum, you'll need a computer equipped with Windows 2000 Professional before you get started. Windows XP Professional will work just fine too, as will any of the Windows 2000 Server packages.

If you don't have one of the required versions of Windows, another option is to secure ASP.NET hosting from someone who does. You can write ASP.NET pages on any operating system; but to run them, you need to put them on a Web server equipped with IIS and ASP.NET.

Other than that, all you need is enough disk space to install IIS (if you haven't already), and a text editor. Notepad will do fine for dabbling, and it's certainly all you'll need for this article, but if you get serious about ASP.NET you'll probably want to invest in a development environment like Visual Studio .NET or Dreamweaver MX.