Commonly Used Types and Namespaces of .NET Framework 3.5 :

Microsoft.Aspnet.Snapin

Contains classes that are necessary for the ASP.NET management console application to interact with the Microsoft Management Console (MMC).

Microsoft.Build.BuildEngine

Contains the classes that represent the MSBuild engine.

Microsoft.Build.Framework

Contains classes that make up the tasks, loggers, and events of MSBuild.

Microsoft.Build.Tasks

Contains the implementation of all tasks shipping with MSBuild.

Microsoft.Build.Tasks.Deployment.Bootstrapper

Contains classes used internally by MSBuild.

Microsoft.Build.Tasks.Deployment.ManifestUtilities

Contains classes used internally by MSBuild.

Microsoft.Build.Utilities

Provides helper classes that you can use to create your own MSBuild loggers and tasks.

Microsoft.Csharp

Contains classes that support compilation and code generation using the C# language.

Microsoft.JScript

Contains classes that support compilation and code generation using the JScript language.

Microsoft.SqlServer.Server

Contains classes that are specific to the integration of the Microsoft .NET Framework common language runtime (CLR) component into Microsoft SQL Server, and the SQL Server database engine process execution environment.

Microsoft.VisualBasic

Contains classes that support compilation and code generation using the Visual Basic language.

Microsoft.VisualBasic.ApplicationServices

Contains types that support the Visual Basic Application Model and provide access to application information.

Microsoft.VisualBasic.CompilerServices

Contains internal-use only types that support the Visual Basic compiler.

Microsoft.VisualBasic.Devices

Contains types that support the My objects related to devices in Visual Basic.

Microsoft.VisualBasic.FileIO

Contains types that support the My file system object in Visual Basic.

Microsoft.VisualBasic.Logging

Contains types that support the My logging objects in Visual Basic and provides a simple log listener that directs logging output to file.

Microsoft.VisualBasic.MyServices

Contains types that support My in Visual Basic.

Microsoft.VisualBasic.MyServices.Internal

Contains internal-use only types that support My in Visual Basic.

Microsoft.VisualBasic.Vsa

Microsoft.VisualC

Microsoft.Vsa

Contains interfaces that allow you to integrate script for the .NET Framework script engines into applications, and to compile and execute code at run time.

Microsoft.Vsa.Vb.CodeDOM

Microsoft.Win32

Provides two types of classes: those that handle events raised by the operating system and those that manipulate the system registry.

Microsoft.Win32.SafeHandles

Contains classes that are abstract derivations of safe handle classes that provide common functionality supporting file and operating system handles.

Microsoft.WindowsCE.Forms

Contains classes for developing Pocket PC and Smartphone Windows Forms applications using the .NET Compact Framework.

Microsoft.WindowsMobile.DirectX

Contains classes for developing DirectX applications on devices with the .NET Compact Framework. Requires a future release of Windows Mobile to run the applications.

Microsoft.WindowsMobile.DirectX.Direct3D

Contains classes for developing Direct3D applications on devices with the .NET Compact Framework. Requires a future release of Windows Mobile to run the applications.

Microsoft_VsaVb

System

Contains fundamental classes and base classes that define commonly used value and reference data types, events and event handlers, interfaces, attributes, and processing exceptions. Other classes provide services supporting data type conversion, method parameter manipulation, mathematics, remote and local program invocation, application environment management, and supervision of managed and unmanaged applications.

System.CodeDom

Contains classes that can be used to represent the elements and structure of a source code document. These elements can be used to model the structure of a source code document that can be output as source code in a supported language using the functionality provided by the System.CodeDom.Compiler namespace.

System.CodeDom.Compiler

Contains types for managing the generation and compilation of source code in supported programming languages. Code generators can each produce source code in a particular programming language based on the structure of Code Document Object Model (CodeDOM) source code models consisting of elements provided by the System.CodeDom namespace.

System.Collections

Contains interfaces and classes that define various collections of objects, such as lists, queues, bit arrays, hashtables and dictionaries.

System.Collections.Generic

Contains interfaces and classes that define generic collections, which allow users to create strongly typed collections that provide better type safety and performance than non-generic strongly typed collections.

System.Collections.ObjectModel

Contains classes that can be used as collections in the object model of a reusable library. Use these classes when properties or methods return collections.

System.Collections.Specialized

Contains specialized and strongly typed collections; for example, a linked list dictionary, a bit vector, and collections that contain only strings.

System.ComponentModel

Provides classes that are used to implement the run-time and design-time behavior of components and controls. This namespace includes the base classes and interfaces for implementing attributes and type converters, binding to data sources, and licensing components.

System.ComponentModel.Design

Contains classes that developers can use to build custom design-time behavior for components and user interfaces for configuring components at design time. The design time environment provides systems that enable developers to arrange components and configure their properties.

System.ComponentModel.Design.Data

Contains classes for implementing design-time behavior of data-related components.

System.ComponentModel.Design.Serialization

Provides types that support customization and control of serialization at design time.

System.Configuration

Contains the types that provide the programming model for handling configuration data.

System.Configuration.Assemblies

Contains classes that are used to configure an assembly.

System.Configuration.Install

Provides classes that allow you to write custom installers for your own components. The Installer class is the base class for all custom installers in the .NET Framework.

System.Configuration.Provider

Contains the base classes shared by both server and client applications to support a pluggable model to easily add or remove functionality.

System.Data

Contains classes that constitute most of the ADO.NET architecture. The ADO.NET architecture enables you to build components that efficiently manage data from multiple data sources. In a disconnected scenario (such as the Internet), ADO.NET provides the tools to request, update, and reconcile data in multiple tier systems. The ADO.NET architecture is also implemented in client applications, such as Windows Forms, or HTML pages created by ASP.NET.

System.Data.Common

Contains classes shared by the .NET Framework data providers. A .NET Framework data provider describes a collection of classes used to access a data source, such as a database, in the managed space.

System.Data.Design

Contains classes that can be used to generate a custom typed-dataset.

System.Data.Linq

Contains classes to access relational data as objects. DataContext and related classes can be used for Reading, Creating, Updating and Deleting objects mapped to a database using mapping specified as attributes in your object model or in a separate external XML file.

System.Data.Linq.Mapping

Provides programmatic access to mapping information used by LINQ to SQL.

System.Data.Odbc

Contains classes that encapsulate the .NET Framework Data Provider for ODBC. The .NET Framework Data Provider for ODBC describes a collection of classes used to access an ODBC data source in the managed space.

System.Data.OleDb

Contains classes that encapsulate the .NET Framework Data Provider for OLE DB. The .NET Framework Data Provider for OLE DB describes a collection of classes used to access an OLE DB data source in the managed space.

System.Data.OracleClient

Contains classes that encapsulate the .NET Framework Data Provider for Oracle. The .NET Framework Data Provider for Oracle describes a collection of classes used to access an Oracle data source in the managed space.

System.Data.Sql

Contains classes that support SQL Server-specific functionality. The API extensions in this class add to the .NET Framework Data Provider for SQL Server (System.Data.SqlClient).

System.Data.SqlClient

Contains classes that encapsulate the .NET Framework Data Provider for SQL Server. The .NET Framework Data Provider for SQL Server describes a collection of classes used to access a SQL Server database in the managed space.

System.Data.SqlServerCE

Describes a collection of classes that can be used to access a database in SQL Server CE from Windows CE-based devices in the managed environment. With this namespace you can create SQL Server CE databases on a device and also establish connections to SQL Server databases that are on a device or on a remote server.

System.Data.SqlTypes

Contains classes for native data types within SQL Server. These classes provide a faster alternative to other data types. Using the classes in this namespace helps prevent type conversion errors caused in situations where loss of precision could occur. Because other data types are converted to and from SqlTypes behind the scenes, explicitly creating and using objects within this namespace results in faster code as well.

System.Diagnostics

Provides classes that allow you to interact with system processes, event logs, and performance counters. This namespace also provides classes that allow you to debug your application and to trace the execution of your code. For more information, see the Trace and Debug classes.

System.Diagnostics.CodeAnalysis

Contains classes for interaction with code analysis tools. Code analysis tools are used to analyze code for conformance to coding conventions such as naming or security rules.

System.Diagnostics.Design

Contains classes that can be used to extend design-time support for application monitoring and instrumentation.

System.Diagnostics.SymbolStore

Provides classes that allow you to read and write debug symbol information, such as source line to Microsoft intermediate language (MSIL) maps. Compilers targeting the .NET Framework can store the debug symbol information into programmer's database (PDB) files. Debuggers and code profiler tools can read the debug symbol information at run time.

System.DirectoryServices

Provides easy access to Active Directory from managed code. The namespace contains two component classes, DirectoryEntry and DirectorySearcher, which use the Active Directory Services Interfaces (ADSI) technology. ADSI is the set of interfaces that Microsoft provides as a flexible tool for working with a variety of network providers. ADSI gives the administrator the ability to locate and manage resources on a network with relative ease, regardless of the network's size.

System.DirectoryServices.ActiveDirectory

Provides a high level abstraction object model that builds around Microsoft® Active Directory® directory service tasks. The Active Directory® directory service concepts such as forest, domain, site, subnet, partition and schema are part of the object model.

System.DirectoryServices.Protocols

Provides the methods defined in the Lightweight Directory Access Protocol (LDAP) version 3 (V3) and Directory Services Markup Language (DSML) version 2 (V2) standards.

System.Drawing

Provides access to GDI+ basic graphics functionality. More advanced functionality is provided in the System.Drawing.Drawing2D, System.Drawing.Imaging, and System.Drawing.Text namespaces.

System.Drawing.Design

Contains classes that extend design-time user interface (UI) logic and drawing. You can further extend this design-time functionality to create custom toolbox items, type-specific value editors that can edit and graphically represent values of their supported types, or type converters that can convert values between certain types. This namespace provides the basic frameworks for developing extensions to the design-time UI.

System.Drawing.Drawing2D

Provides advanced 2-dimensional and vector graphics functionality. This namespace includes the gradient brushes, the Matrix class (used to define geometric transforms), and the GraphicsPath class.

System.Drawing.Imaging

Provides advanced GDI+ imaging functionality. Basic graphics functionality is provided by the System.Drawing namespace.

System.Drawing.Printing

Provides print-related services. Typically, you create a new instance of the PrintDocument class, set the properties that describe what to print, and call the Print method to actually print the document.

System.Drawing.Text

Provides advanced GDI+ typography functionality. Basic graphics functionality is provided by the System.Drawing namespace. The classes in this namespace allow users to create and use collections of fonts.

System.EnterpriseServices

Provides an important infrastructure for enterprise applications. COM+ provides a services architecture for component programming models deployed in an enterprise environment. This namespace provides .NET Framework objects with access to COM+ services, making the .NET Framework objects more practical for enterprise applications.

System.EnterpriseServices.CompensatingResourceManager

Provides classes that allow you to use a Compensating Resource Manager (CRM) in managed code. A CRM is a service provided by COM+ that enables you to include non-transactional objects in Microsoft Distributed Transaction Coordinator (DTC) transactions. Although CRMs do not provide the capabilities of a full resource manager, they do provide transactional atomicity (all-or-nothing behavior) and durability through the recovery log.

System.EnterpriseServices.Internal

Provides infrastructure support for COM+ services. The classes and interfaces in this namespace are specifically intended to support calls into System.EnterpriseServices from the unmanaged COM+ classes.

System.Globalization

Contains classes that define culture-related information, including the language, the country/region, the calendars in use, the format patterns for dates, currency, and numbers, and the sort order for strings. These classes are useful for writing globalized (internationalized) applications.

System.IO

Contains types that allow synchronous and asynchronous reading and writing on data streams and files.

System.IO.Compression

Contains classes that provide basic compression and decompression for streams.

System.IO.IsolatedStorage

Contains types that allow the creation and use of isolated stores. With these stores, you can read and write data that less trusted code cannot access and help prevent the exposure of sensitive information that can be saved elsewhere on the file system. Data is stored in compartments that are isolated by the current user and by the assembly in which the code exists.

System.IO.Ports

Contains classes that control serial ports, providing a framework for synchronous and event-driven I/O, access to pin and break states, access to serial driver properties, and enumerations for specifying port characteristics.

System.Linq

Provides classes and interfaces that support queries that use Language-Integrated Query (LINQ).

System.Linq.Expressions

Contains classes, interfaces and enumerations that enable language-level code expressions to be represented as objects in the form of expression trees.

System.Management

Provides access to a rich set of management information and management events about the system, devices, and applications instrumented to the Windows Management Instrumentation (WMI) infrastructure.

System.Management.Instrumentation

Provides the classes necessary for instrumenting applications for management and exposing their management information and events through WMI to potential consumers. Consumers such as Microsoft Application Center or Microsoft Operations Manager can then manage your application easily, and monitoring and configuring of your application is available for administrator scripts or other applications, both managed as well as unmanaged.

System.Messaging

Provides classes that allow you to connect to, monitor, and administer message queues on the network and send, receive, or peek messages.

System.Messaging.Design

Contains classes that can be used to extend design-time support for System.Messaging classes.