System.IO.FileSystem by: Microsoft

Provides types that allow reading and writing to files and types that provide basic file and directory support. Commonly Used Types: System.IO.FileStream System.IO.FileInfo System.IO.DirectoryInfo System.IO.FileSystemInfo System.IO.File System.IO.Directory System.IO.SearchOption System.IO.FileOptions

System.Linq.Dynamic.3.5 by: Microsoft

System.Linq.Dynamic for .NET 3.5 compiled .dll packaged for NuGet

System.Net.NameResolution by: Microsoft

Provides the System.Net.Dns class, which enables developers to perform simple domain name resolution. Commonly Used Types: System.Net.Dns System.Net.IPHostEntry

System.Linq by: Microsoft

Provides classes and interfaces that supports queries that use Language-Integrated Query (LINQ). Commonly Used Types: System.Linq.Enumerable System.Linq.IGrouping<TKey, TElement> System.Linq.IOrderedEnumerable<TElement> System.Linq.ILookup<TKey, TElement> System.Linq.Lookup<TKey, TElement>

System.IO.MemoryMappedFiles by: Microsoft

Provides classes for using a memory-mapped file, which maps the contents of a file to an application's logical address space. Commonly Used Types: System.IO.MemoryMappedFiles.MemoryMappedViewAccessor System.IO.MemoryMappedFiles.MemoryMappedViewStream System.IO.MemoryMappedFiles.MemoryMappedFile System.IO.MemoryMappedFiles.MemoryMappedFileAccess

System.Linq.Queryable by: Microsoft

Provides classes for querying data structures that implement IQueryable<T>. Commonly Used Types: System.Linq.Queryable System.Linq.EnumerableQuery<T> System.Linq.EnumerableQuery

System.IO.UnmanagedMemoryStream by: Microsoft

Provides classes for access to unmanaged blocks of memory from managed code. Commonly Used Types: System.IO.UnmanagedMemoryStream System.IO.UnmanagedMemoryAccessor

System.IO.FileSystem.Watcher by: Microsoft

Provides the System.IO.FileSystemWather class, which listens to the file system change notifications and raises events when a directory, or a file in a directory, changes. Commonly Used Types: System.IO.FileSystemWatcher System.IO.WatcherChangeTypes System.IO.FileSystemEventArgs System.IO.RenamedEventArgs System.IO.FileSystemEventHandler System.IO.RenamedEventHandler System.IO.NotifyFilters System.IO.ErrorEventArgs System.IO.ErrorEventHandler System.IO.WaitForChangedResult

System.IO.Abstractions by: Tatham Oddie

Just like System.Web.Abstractions, but for System.IO. Yay for testable IO access!

System.Linq.Expressions by: Microsoft

Provides classes, interfaces and enumerations that enable language-level code expressions to be represented as objects in the form of expression trees. Commonly Used Types: System.Linq.Expressions.Expression<TDelegate> System.Linq.Expressions.Expression System.Linq.Expressions.MemberExpression System.Linq.Expressions.ExpressionVisitor System.Linq.Expressions.MethodCallExpression System.Linq.IQueryable<T> System.Linq.IQueryable System.Linq.Expressions.NewExpression System.Linq.Expressions.ParameterExpression System.Linq.Expressions.ConstantExpression

System.IO.FileSystem.DriveInfo by: Microsoft

Provides the System.IO.DriveInfo class, which enables developers to query local drive information. Commonly Used Types: System.IO.DriveInfo System.IO.DriveType System.IO.DriveNotFoundException

System.IO.Pipes by: Microsoft

Provides a means for interprocess communication through anonymous and/or named pipes. Commonly Used Types: System.IO.Pipes.NamedPipeServerStream System.IO.Pipes.PipeDirection System.IO.Pipes.PipeOptions System.IO.Pipes.PipeTransmissionMode System.IO.Pipes.NamedPipeClientStream System.IO.Pipes.PipeStream

System.Net.Http by: Microsoft

Provides modern classes for sending HTTP requests and receiving HTTP responses from a resource identified by a URI. Commonly Used Types: System.Net.Http.HttpResponseMessage System.Net.Http.DelegatingHandler System.Net.Http.HttpRequestException System.Net.Http.HttpClient System.Net.Http.MultipartContent System.Net.Http.Headers.HttpContentHeaders System.Net.Http.HttpClientHandler System.Net.Http.StreamContent System.Net.Http.FormUrlEncodedContent System.Net.Http.HttpMessageHandler

System.IO.Compression by: Microsoft

Provides classes that support the compression and decompression of streams. Commonly Used Types: System.IO.Compression.DeflateStream System.IO.Compression.GZipStream System.IO.Compression.CompressionMode System.IO.Compression.CompressionLevel System.IO.Compression.ZipArchiveEntry System.IO.Compression.ZipArchive System.IO.Compression.ZipArchiveMode

System.Linq.Parallel by: Microsoft

Provides classes that supports parallel queries that use Language-Integrated Query (LINQ). Commonly Used Types: System.Linq.ParallelQuery<TSource> System.Linq.ParallelEnumerable System.Linq.ParallelQuery System.Linq.OrderedParallelQuery<TSource>

System.IO.FileSystem.Primitives by: Microsoft

Provides common enumerations and exceptions for path-based I/O libraries. Commonly Used Types: System.IO.DirectoryNotFoundException System.IO.FileAccess System.IO.FileLoadException System.IO.PathTooLongException System.IO.FileMode System.IO.FileShare System.IO.FileAttributes

System.Net.Http.WinHttpHandler by: Microsoft

Provides access to a high performance HTTP client handler based on the native Windows HTTP Services (WinHTTP) API. Commonly Used Types: System.Net.Http.WinHttpHandler

System.IO.Compression.ZipFile by: Microsoft

Provides classes that support the compression and decompression of streams using file system paths. Commonly Used Types: System.IO.Compression.ZipFile

System.Management.Automation by: Microsoft

Runtime for hosting PowerShell

System.Net.NetworkInformation by: Microsoft

Provides access to network traffic data, network address information, and notification of address changes for the local computer. Commonly Used Types: System.Net.NetworkInformation.NetworkInterface System.Net.NetworkInformation.NetworkInformationException System.Net.NetworkInformation.NetworkAddressChangedEventHandler System.Net.NetworkInformation.NetworkInterfaceType System.Net.NetworkInformation.OperationalStatus System.Net.NetworkInformation.IPGlobalProperties System.Net.NetworkInformation.UnicastIPAddressInformation System.Net.NetworkInformation.UnicastIPAddressInformationCollection System.Net.NetworkInformation.PhysicalAddress System.Net.NetworkInformation.TcpConnectionInformation