Overview of the .NET Framework[1]

Overview of the .NET Framework
Clearly, a considerable amount of infrastructure is required to make XML Web
Services transparent to the developers and users. The .NET Framework
provides that infrastructure. To the .NET Framework, all components can be
XML Web Services, and XML Web Services are just a kind of component. In
effect, the .NET Framework takes the best aspects of the Microsoft
Component Object Model (COM) and combines them with the best aspects of
loosely coupled, XML-based computing. The result is a powerful, productive
Web component system that simplifies programmer plumbing, deeply integrates
security, introduces an Internet-scale deployment system, and greatly
improves application reliability and scalability.

The .NET Framework consists of two main parts: the Common Language Runtime
(CLR) and a set of unified class libraries. The class libraries include
versions of many of Microsoft's existing development technologies, such as
an advanced version of Active Server Pages, called ASP.NET, a set of
classes for rich user interface development, called Windows Forms, and a
data-access subsystem called ADO.NET. All these existing libraries have
been updated to be XML aware within the .NET Framework.

The Common Language Runtime
Despite its name, the Common Language Runtime actually has a role in a
component's development time and runtime experiences. While the component
is running, the runtime is responsible for managing memory allocation,
starting up and killing threads and processes, enforcing security policy,
and satisfying any dependencies that the component may have on other
components. At development time, the runtime's role changes slightly.
Because it automates so much (for example, memory management), the runtime
makes the developer's experience very simple, especially when compared to
COM today. In particular, features such as reflection dramatically reduce
the amount of code a developer must write in order to turn business logic
into a reusable component.

Runtimes are nothing new for languages梫irtually every programming language
has a runtime. Visual Basic has the most obvious runtime (the aptly named
VBRUN), but Visual C++ has one (MSVCRT), as do FoxPro, JScript, Smalltalk,
Perl, Python, and Java. The .NET Framework's critical role, and what really
sets it apart, is that it provides a unified runtime and development
environment across all programming languages.

The .NET Classes
The .NET Framework's classes provide a unified, object-oriented,
hierarchical, extensible set of class libraries (APIs) for developers to
use. Today, C++ developers will use the Microsoft Foundation Classes, Java
developers will use the Windows Foundation Classes or J2EE, and Visual
Basic developers will use VB's APIs. Simply put, the .NET CLR unifies the
disparate frameworks Microsoft has today. The result is that dev-elopers no
longer have to learn multiple frameworks when working in multiple
languages. By creating a common set of APIs across all programming
languages, the .NET Framework enables cross-language inheritance, error
handling, and debugging. In effect, all programming languages, from JScript
to C++, become equals, and developers are free to choose the language they
want to use.

Here are some of the key benefits of the .NET Framework for developers:

Can use any .NET-enabled programming language. The .NET Framework enables
developers to use any .NET-enabled programming language, and it enables
applications written in these languages to integrate deeply with each
other, which means current development skills can be used right away within
the same project and future projects.

Can write less code. The .NET Framework uses a highly "componentized,"
plumbing-free design that enables developers to focus on writing business
logic. Developers don't need to write Interface Definition Language (IDL)
or Registry code anymore. ASP.NET, for example, includes dozens of controls
that encapsulate common programmer tasks, such as user validation, creating
calendars and ad rotators, and much more.

Can use XML and SOAP without learning these technologies. The .NET
Framework was built for delivering software as a service, so it is built on
XML and the SOAP family of integration standards. Simply annotate method
calls and the .NET Framework turns them into full XML Web Services. You do
not need to learn these underlying technologies because the .NET Framework
wraps classes around them.

Can run more reliable applications. The .NET Framework includes
technologies to make applications more reliable. For example, memory,
threads, and processes are m