System.Diagnostics.DiagnosticSource by: Microsoft

Provides Classes that allow you to decouple code logging rich (unserializable) diagnostics/telemetry (e.g. framework) from code that consumes it (e.g. tools) Commonly Used Types: System.Diagnostics.DiagnosticListener System.Diagnostics.DiagnosticSource

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.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.Runtime.Loader by: Microsoft

Provides the System.Runtime.Loader.AssemblyLoadContext class, which provides members for loading assemblies. Commonly Used Types: System.Runtime.Loader.AssemblyLoadContext

System.Runtime.Serialization.Json by: Microsoft

Provides classes for serializing objects to the JavaScript Object Notation (JSON) and deserializing JSON data to objects. Commonly Used Types: System.Runtime.Serialization.Json.DataContractJsonSerializer

System.Security.Principal by: Microsoft

Provides the base interfaces for principal and identity objects that represents the security context under which code is running.

System.ServiceModel.Security by: Microsoft

Provides common security types for consuming and communicating with services. Commonly Used Types: System.ServiceModel.DnsEndpointIdentity System.ServiceModel.MessageSecurityVersion System.ServiceModel.UpnEndpointIdentity System.ServiceModel.SpnEndpointIdentity

System.Text.Encoding by: Microsoft

Provides base abstract encoding classes for converting blocks of characters to and from blocks of bytes. Commonly Used Types: System.Text.Encoding System.Text.DecoderFallbackException System.Text.Decoder System.Text.EncoderFallbackException System.Text.Encoder System.Text.EncoderFallback System.Text.EncoderFallbackBuffer System.Text.DecoderFallback System.Text.DecoderFallbackBuffer System.Text.DecoderExceptionFallback

System.Threading.Overlapped by: Microsoft

Provides common types for interacting with asynchronous (or overlapped) input and output (I/O). Commonly Used Types: System.Threading.NativeOverlapped System.Threading.Overlapped System.Threading.IOCompletionCallback

System.Xml.XPath by: Microsoft

Provides the classes that define a cursor model for navigating and editing Extensible Markup Language (XML) information items as instances of the XQuery 1.0 and XPath 2.0 Data Model.

Tizen.NET.API4 by: Samsung Electronics

Reference assemblies of Tizen .NET API Level 4.

Xamarin.Android.Support.Media.Compat by: Xamarin Inc.

Media Compat Android Support Library C# bindings for Xamarin

Xamarin.Build.Download by: Microsoft

Support for downloading and unpacking archives when building MSBuild projects

Xamarin.Facebook.ShareKit.iOS by: Microsoft

C# binding for Facebook ShareKit's official SDK

Xamarin.Firebase.iOS.Analytics by: Microsoft

C# bindings for Firebase APIs Analytics iOS Library

xunit.analyzers by: jnewkirk, bradwilson, marcind

xUnit.net is a developer testing framework, built to support Test Driven Development, with a design goal of extreme simplicity and alignment with framework features. Installing this package provides code analyzers to help developers find and fix frequent issues when writing tests and xUnit.net extensibility code.

xunit.core by: jnewkirk, bradwilson

Includes the libraries for writing unit tests with xUnit.net.