Advanced ASP .NET Server-side ControlsDuring the mid-90s, you could create rich, active Web sites by trying to extend the browser—primarily through ActiveX® controls or Java-language applets. Unfortunately this approach presented several problems, the most limiting being that not every client site supported these technologies. This is especially true now with the rapid proliferation of next-generation devices. No longer can you count on one or two well-known client environments—the client to your Web site may be any of a huge number of potential devices, ranging from small handheld devices or cell phones to full-blown desktop computers. The Microsoft® .NET Framework solves this problem by having the server generate the user interface code as pure HTML (as well as newer standards like WML and XHTML) and then squirting the HTML out to the browser. Because every browser understands HTML, that's a reasonable way to get UI presentation out to the client. At the heart of the .NET platform is ASP .NET.