Stateless by: Stateless Contributors

Create state machines and lightweight state machine-based workflows directly in .NET code

StreamJsonRpc by: Microsoft

A cross-platform .NET portable library that implements the JSON-RPC wire protocol and can use System.IO.Stream or WebSocket so you can use it with any transport.

Stripe.net by: Stripe, Jayme Davis

Stripe.net is a sync/async .NET 4.5+ client, and a portable class library for the Stripe API. (Official Library)

StrongNamer by: Daniel Plaisted

Strong Namer will automatically add strong names to referenced assemblies which do not already have a strong name.

StyleCop.Analyzers by: Sam Harwell et. al.

An implementation of StyleCop's rules using Roslyn analyzers and code fixes

StyleCop.Analyzers.Unstable by: Sam Harwell et. al.

An implementation of StyleCop's rules using Roslyn analyzers and code fixes

StyleCop.MSBuild by: StyleCop contributors, Chris Dahlberg

Integrates StyleCop "Classic" source code analysis into the build process of C# projects to enforce a set of style and consistency rules.

Stylet by: Antony Male

A very lightweight but powerful ViewModel-First MVVM framework for WPF, inspired by Caliburn.Micro. Comes with its own IoC container.

SuperSocket by: Kerry Jiang

SuperSocket is a light weight, cross platform and extensible socket server application framework. You can use it to build a server side socket application (like game server, GPS server, industrial control system, data acquisition server etc) easily without thinking about how to use socket, how to maintain the socket connections and how socket works.

SuperSocket.ProtoBase by: Kerry Jiang

It is a network protocol resolving library which can be used in both server and client

SuperSocket.WebSocket by: Kerry Jiang

WebSocket server implementation base on SuperSocket. It is just the same codebase with SuperWebSocket but has different assembly name and namespace.

Svg by: mrbean-bremen, davescriven, jvenema, owaits, ddpruitt, Ralf1108, Tebjan Halm, and others

Public fork of the C# SVG rendering library on codeplex: https://svg.codeplex.com/ This started out as a minor modification to enable the writing of proper SVG strings. But now after almost two years we have so many fixes and improvements that we decided to share our current codebase to the public in order to improve it even further. So please feel free to fork it and open pull requests for any fix, improvement or feature you add. License: Microsoft Public License: https://svg.codeplex.com/license

Swashbuckle.AspNetCore by: domaindrivendev

Swagger tools for documenting APIs built on ASP.NET Core

System.AppContext by: Microsoft

Provides the System.AppContext class, which allows access to the BaseDirectory property and other application specific data. Commonly Used Types: System.AppContext

System.Binary by: Microsoft Corporation

Non-allocating ninary reader and writer

System.Buffers by: Microsoft

Provides resource pooling of any type for performance-critical applications that allocate and deallocate objects frequently. Commonly Used Types: System.Buffers.ArrayPool<T> 7601f4f6225089ffb291dc7d58293c7bbf5c5d4f When using NuGet 3.x this package requires at least version 3.4.

System.Buffers.Primitives by: Microsoft Corporation

Slices of arrays and buffers

System.Collections by: Microsoft

Provides classes that define generic collections, which allow developers to create strongly typed collections that provide better type safety and performance than non-generic strongly typed collections. Commonly Used Types: System.Collections.Generic.List<T> System.Collections.Generic.Dictionary<TKey, TValue> System.Collections.Generic.Queue<T> System.Collections.Generic.Stack<T> System.Collections.Generic.HashSet<T> System.Collections.Generic.LinkedList<T> System.Collections.Generic.EqualityComparer<T> System.Collections.Generic.Comparer<T> System.Collections.Generic.SortedDictionary<TKey, TValue>

System.Collections.Concurrent by: Microsoft

Provides several thread-safe collection classes that should be used in place of the corresponding types in the System.Collections.NonGeneric and System.Collections packages whenever multiple threads are accessing the collection concurrently. Commonly Used Types: System.Collections.Concurrent.ConcurrentDictionary<TKey, TValue> System.Collections.Concurrent.ConcurrentQueue<T> System.Collections.Concurrent.ConcurrentBag<T> System.Collections.Concurrent.BlockingCollection<T> System.Collections.Concurrent.ConcurrentStack<T>

System.Collections.Immutable by: Microsoft

This package provides collections that are thread safe and guaranteed to never change their contents, also known as immutable collections. Like strings, any methods that perform modifications will not change the existing instance but instead return a new instance. For efficiency reasons, the implementation uses a sharing mechanism to ensure that newly created instances share as much data as possible with the previous instance while ensuring that operations have a predictable time complexity. Commonly Used Types: System.Collections.Immutable.ImmutableArray System.Collections.Immutable.ImmutableArray<T> System.Collections.Immutable.ImmutableDictionary System.Collections.Immutable.ImmutableDictionary<TKey,TValue> System.Collections.Immutable.ImmutableHashSet System.Collections.Immutable.ImmutableHashSet<T> System.Collections.Immutable.ImmutableList System.Collections.Immutable.ImmutableList<T> System.Collections.Immutable.ImmutableQueue System.Collections.Immutable.ImmutableQueue<T> System.Collections.Immutable.ImmutableSortedDictionary System.Collections.Immutable.ImmutableSortedDictionary<TKey,TValue> System.Collections.Immutable.ImmutableSortedSet System.Collections.Immutable.ImmutableSortedSet<T> System.Collections.Immutable.ImmutableStack System.Collections.Immutable.ImmutableStack<T>