Windows DNA

Windows DNA, or, as it's becoming, the Windows DNA 2000 platform, is supported by a comprehensive set of application services on the Windows operating systems. As we said, the basic idea behind Windows DNA is to provide us, as developers, with a set of tools enabling us to easily create the application infrastructure, so that we can concentrate on the logic that's specific to the business problem being solved. These infrastructure services are covered in more detail in later chapters as we use them, but they include support for building Web-based applications, support for transactions, and a unifying component model.

With the release of Windows 2000 and associated products this area is in a state of transition, and the precise technologies you're likely to use to develop an application will depend on the platform your client is using. Of course there is an easy migration path between the different technologies, and in this book we'll show you how to develop for both Windows 9x/NT 4.0 and Windows 2000 platforms.

So, for 3-tier development in a Windows 9x/NT 4.0 environment the tools at our disposal include:

• Microsoft Transaction Server (MTS) – A rich set of integrated services that makes it easy to build multi-user server-side components and perform transactions across multiple data sources

• Microsoft Internet Information Server (IIS) – Web server software

• Active Server Pages (ASP) – A server-side scripting technology that makes it easy to build Web pages that are both dynamic and interactive

• Microsoft Component Object Model (COM) – A foundation for creating distributed applications built from components

• Microsoft Message Queue Server (MSMQ) – A flexible, reliable approach to communication between applications

• Universal Data Access (UDA) – A set of data access services, including an easy-to-use high-level programming interface ActiveX Data Objects (ADO)

• Microsoft SQL Server 7.0 – A relational database management system for the Microsoft Windows platform

In Windows 2000 there are the following variations:

• MTS has been merged with COM and is part of COM+

• IIS is called Internet Information Services

With the exception of SQL Server 7.0, all these technologies are currently included with the
Windows 2000 Server series of operating systems. However, the situation is slightly different for users of Win 9x or NT 4.0. We'll discuss exactly what software you need to make the most of this book (and how to obtain it) at the end of the chapter.

Let's now expand slightly on what these technologies can do for us, and where we are likely to encounter them.