When Microsoft formally introduced its .NET strategy in mid-2000, analysts were confused about how the company would pull off such a massive platform shift. Two years later, they're still wondering. But .NET isn't vaporware, and it's not a pipe dream. In fact, .NET is happening today. If you've got a question about this exciting set of technologies, please ask me and I'll post the answer here.

Q: What is .NET?
A: It's a dessert topping, it's a floor cleaner--it's a dessert topping and a floor cleaner! Actually, .NET is many things, but primarily it's a marketing term for a set of products and technologies that Microsoft is creating to move personal and enterprise computing beyond the PC desktop and into a distributed Internet-based environment. So .NET--which was originally called Next Generation Windows Services (NGWS)--is also a platform, one that Microsoft sees as the successor to Windows. The .NET platform is based on Web services which are, in turn, defined by a language called XML.

Q: What is XML?
A: XML--the eXtensible Markup Language--is a self-descriptive, data definition language. It's similar to HTML, the language of the Web, but it's far more powerful because it's not limited to a static list of language constructs ("tags") that the language's authors supply. Instead, XML is extensible and dynamic: Programmers can define new types of data using XML and then describe that data so that others will know how to use it.

Q: What are Web services?
A: Web services are server-side applications that expose their services as programmable units that other applications (and Web services) can access over the Internet.

Q. Does .NET require Windows?
A. Technically, no, but realistically, yes. It's possible the .NET platform could be ported to other operating systems, such as Linux, FreeBSD, the Macintosh, or whatever, and indeed, some work is being done now in this area. However, .NET very much requires Windows today, on both the server and the client. One might say that .NET and Windows have a symbiotic relationship.

Q: .NET is being ported to Linux?
A. Yes. A company called Ximian is porting the standards-based parts of .NET to Linux as you read this, and the work is amazingly far along. Code-named Mono, this project seeks to bring the C# programming language, the Common Language Runtime (CLR, see below), and other .NET features to Linux.

On a related note, Microsoft has contracted Corel (makers of CorelDRAW and Word Perfect) to port .NET to FreeBSD at some undetermined date in the future. This project has not yet started.

Q: Which Windows versions support .NET?
A: You can run .NET client applications and services on Windows 98, 98 SE, Millennium Edition (Me), NT 4.0, 2000, or XP. Beginning in late 2002, you will be able to run .NET applications and services on Windows CE .NET products, such as the Pocket PC and Microsoft Smart Phone, as well.

On the server, you can use Windows NT 4.0, 2000, or .NET Server.

Q: Are there any .NET features in Windows XP?
A. Yes, but not much. Because Windows XP was designed and built before the .NET Framework was complete, it only includes bare-bones .NET functionality. The primary conduit for .NET in XP is Windows Messenger, which is used to expose .NET alert and rendezvous services. XP also includes integration with the .NET Passport service, so that you can optionally auto-logon to Passport when you logon to Windows.

Q: Isn't .NET just another name for COM, COM+, Windows DNA, or some other previous Windows technology?
A: Actually, no. Microsoft spent considerable time and effort developing and promoting a set of Windows technologies that was at various times called OLE, COM, COM+, and Windows DNA (Distributed InterNet Architecture) but .NET is not the next iteration. Windows DNA, which was the final umbrella term for this set of technologies, was based around a concept where Windows-based software components could expose their services for other local and remote Windows software components. But though this sounds passingly similar to .NET, Windows DNA is very much based on proprietary Windows technologies. By comparison, .NET is based on open standards (XML and various related technologies), so it will be much easier for other vendors to adopt the platform and write compatible software. So we can eventually expect to see .NET clients and servers on platforms other than Windows.

Q: So are all older applications useless now? What about all those COM components I developed over the past several years?
A. Obviously, any existing applications, services, and components will continue to work with future Windows versions. However, Microsoft has also added interoperability features so that you can use this older code--now referred to as unmanaged code--with new .NET applications and services.

Q: So what technologies are part of .NET?
A: .NET is comprised of several related technologies, including:

.NET Framework - A runtime environment and set of standard services which .NET capable applications and services can utilize. Implemented as a code library, the .NET Framework includes the Common Language Runtime (CLR), the .NET run-time environment; ASP .NET, a Web applications platform; and ADO .NET, for data store access. Microsoft will ship a version of the .NET Framework--dubbed the .NET Compact Framework--for Pocket PCs, Microsoft Smart Phones, and other similar devices in late 2002.

.NET My Services - A set of free, consumer-oriented services that will expand on .NET Passport's authentication services (available today) to offer Web server-based storage of personal information such as name and address, calendar, address book, and credit card information. Microsoft expects to ship .NET My Services (previously code-named Hailstorm) for consumers by the end of 2002. A business oriented version of .NET My Services is also in the works.

.NET Enterprise Servers - A set of expensive Microsoft server software that runs on Windows servers, including Application Server, BizTalk Server, Exchange Server, Host Integration Server, Internet Security and Acceleration Server, SQL Server, and many others. Microsoft is currently shipping many such server products, but they are all based on Windows DNA currently, not .NET. Future server products--beginning with Windows .NET Server, due in late 2002--will actually be based on .NET technologies for the first time.

Visual Studio .NET - Microsoft's .NET development environment, with support for languages such as Visual Basic .NET, Visual C++ .NET, and Visual C# .NET, which all target the .NET Framework. Other vendors can add other language capabilities to Visual Studio .NET, and the suite can be used to target a wide range of applications and services, including .NET Web services, Windows applications, and Web applications. Note that Visual Studio .NET is not required to create .NET applications and services: Developers can download the .NET Framework for free; this download includes compilers for Visual Basic .NET, Visual C++ .NET and Visual C# .NET.

Q: Will I need to upgrade my Windows NT4/2000 servers to Windows .NET Server to serve .NET applications and services?
A. No, you can install the .NET Framework on Windows NT 4.0 or Windows 2000. However, Microsoft hopes that it's new .NET Enterprise Servers add enough value that you will want to upgrade to one or more of them.

Q: What does Windows .NET Server bring to the picture compared to Windows 2000 Server?
A. Windows .NET Server is a minor upgrade to Windows 2000 Server, but I'll have more information about this product when Release Candidate 1 (RC1) hits sometime this summer. In the meantime, check out my review of Windows .NET Server Beta 3.

Q: Visual Studio .NET sounds nice, but what about other programming languages?
A. One of the biggest advancements in Visual Studio .NET is that the environment, like the underlying .NET CLR, is not tied to any one language. Microsoft ships C#, C++, Visual Basic, and ECMAScript/JScript/JavaScript support in the box, and will ship its Visual J# .NET add-on later in 2002. But hundreds of companies are porting various programming languages to .NET and the Visual Studio .NET environment, including Delphi/Object Pascal, Perl, PHP, and many more.

Q. What if I want to create standalone Windows applications that don't rely on the .NET Framework? Is this still possible?
A. You can still write Visual C++ applications and services that rely on technology such as the Win32 API, MFC, ATL, or COM/COM+. However, Visual Basic programmers will have to learn the new Windows Form model exposed by the .NET Framework.

Q: What's the future of Web-based scripting under .NET? If one wanted to write Web scripts that work with the widest variety of browsers?
A. You want to look into something called ASP .NET, which is a server-side scripting environment. What this gives you is the ability to use any .NET compatible language, built-in browser detection features you won't need to hand-code, and compatibility with non-PC devices like Smart Phones and Pocket PCs. The future of Web scripting is server-side.

Q: When will the .NET Framework be shipped as part of Windows? Will it be included in Windows 2000 SP3 or Windows XP SP1?
A. Windows .NET Server will be the first Windows version to ship with the .NET Framework included as an integral component; this product is due in late 2002. I've asked Microsoft whether the .NET Framework will be included in Windows 2000 SP3 and/or Windows XP SP1 (both due later this year) but the company is unwilling to discuss this topic until later. My guess is that, no, the .NET Framework will not be part of these releases.

Q: Parts of .NET sounds a lot like Java. Is it just a Java rip-off?
A. Not exactly. Like Java, .NET includes a run-time environment that provides a number of important developer services, such as garbage protection. And yes, C#--an object oriented, C-like programming language similar to Java--is the preferred language for .NET development. But Java isn't the first object-oriented C-like language, and it certainly isn't the first developer tool to offer a run-time environment (indeed, Microsoft has used a run-time environment for Visual Basic for almost a decade, beginning well before Java was invented).

Also, .NET offers three critical advantages over Java: First, it allows the programmer to use any compatible programming language, compared to the one (Java) that the Java environment allows. Secondly, .NET applications and services are fully compiled, unlike Java applications and services, so they offer much better performance. And finally, critical portions of .NET--including the CLR and the C# programming language--have been opened as international standards. Despite promises, Java's inventor--Sun Microsystems--has constantly reneged on its Java standardization efforts. This standards-based approach will eventually see .NET ported to operating systems other than Windows.

Q: What about Windows? If .NET is successful, does that mean Windows goes away?
A: No. Windows is a crucial component of .NET, on both the server and the client (desktop). Server-side, Windows servers will be used to execute .NET code and provide .NET services to users. On the client, a future Windows version called Windows .NET will provide pervasive .NET integration and be what Microsoft calls the most complete .NET client. And on handheld and connected devices, Windows CE .NET will offer a subset of the .NET Framework called the .NET Compact Framework, that enables .NET compatibility there as well. Even if .NET succeeds beyond Microsoft's wildest dreams, Windows doesn't go away. Instead, it becomes a key component of a far wider strategy that moves beyond the PC to include PC-like devices such as cell phones, PDAs, set-top boxes, and the like.

Q: What about 64-bit Windows versions? Will .NET applications and services have to be recoded or recompiled to run on this new platform?
A. Most .NET applications and services should run fine on 64-bit Windows platforms that are .NET Framework-enabled without having to be recoded or recompiled at all.

Q: .NET sounds like it requires a 24/7 Internet connection. What happens when that connection goes down, or if we have a dial-up Internet connection?
A. For .NET to be fully realized, bandwidth will have to be like electricity. That is, it will have to be always on, and very reliable. In the meantime, Microsoft realizes that many people will be accessing .NET services through an unreliable or slow connection, and for this reason, the technology is being built to deal gracefully with interruptions.

Q: How do we know .NET isn't just a passing fad?
A. I think the clearest way to understand