Framework Class Library (fcl)   C#
Text System.Text
System.Text.RegularExpressions
Collections System.Collections
System.Collections.Specialized
Streams and I/O System.IO
System.IO.IsolatedStorage
Networking System.Net
System.Net.Sockets
Threading System.Threading
System.Timers
Security System..Security
System..Security.Crytography
System..Security.Crytography.X509Certificates
System..Security.Crytography.Xml
System..Security.Permissions
System..Security.Policy
System..Security.Principal
Reflection and Metadata System.Reflection
System.Reflection.Emit
Assemblies System.Reflection
Serialization System.Runtime.Serialization
System.Runtime.Serialization.Formatters
System.Runtime.Serialization.Formatters.Soap
System.Runtime.Serialization.Formatters.Binary
Remoting System.Runtime.Remoting
System.Runtime.Remoting.Activation
System.Runtime.Remoting.Channels
System.Runtime.Remoting.Channels.Http
System.Runtime.Remoting.Channels.Tcp
System.Runtime.Remoting.Contexts
System.Runtime.Remoting.Lifetime
System.Runtime.Remoting.Messaging
System.Runtime.Remoting.Metadata
System.Runtime.Remoting.MetadataServices
System.Runtime.Remoting.Proxies
System.Runtime.Remoting.Services
Web Services System.Web.Services
System.Web.Services.Configuration
System.Web.Services.Description
System.Web.Services.Discovery
System.Web.Services.Protocols
Data Access System.Data
System.Data.Common
System.Data.OleDb
System.Data.SqlClient
System.Data.SqlTypes
XML System.Xml
System.Xml.Schema
System.Xml.Serialization
System.Xml.XPath
System.Xml.Xsl
Graphics System.Drawing
System.Drawing.Design
System.Drawing.Drawing2D
System.Drawing.Imaging
System.Drawing.Printing
System.Drawing.Text
Rich Client Applications System.Windows.Forms
System.Windows.Forms.Design
Web Based Applications System.Web
System.Web.Catching
System.Web.Configuration
System.Web.Hosting
System.Web.Mail
System.Web.Security
System.Web.SessionState
System.Web.UI
System.Web.UI.Design
System.Web.UI.Design.WebControls
System.Web.UI.HtmlControls
System.Web.UI.WebControls
Globalization System.Globalization
System.Resources
Configuration System.Configuration
System.Configuration.Assemblies
System.Configuration.Install
Advanced Component Serevices System.DirectoryServices
System.EnterpriseServices
System.EnterpriseServices.CompensatingResourceManager
System.Messaging
Diagnostics and Debugging System.Diagnostics
System.Diagnostics.SymbolStore
Interoperating with Unmanaged Code System.Runtime.Interoperating
System.Runtime.Interoperating.CustomMarshalers
System.Runtime.Interoperating .Expando
Compiler and Tool Support Microsoft.CSharp
MicrosoftJScript
Microsoft.VisualBasic
Microsoft.Vsa
System.CodeDom
System.CodeDom.Compiler
System.ComponentModel
System.ComponentModel.Design
System.ComponentModel.Design.Serialization
System.Runtime.CompilerServices
Runtime Facilities System
Native OS Facilities Microsoft.Win32
System,Management
System,Management.Instrumentation
System.ServiceProcess