An open source fork of Windows Live Writer

One framework for creating powerful cross-platform games.

Every programmer needs a rubberduck. COM add-in for the VBA & VB6 IDE (VBE).

A cross-platform plotting library for .NET

Lean Algorithmic Trading Engine by QuantConnect (Python, C#)

A wrapper executable that can run any executable as a Windows service, in a permissive license.

.NET for Apache® Spark™ makes Apache Spark™ easily accessible to .NET developers.

Open Source Web Application Framework for ASP.NET Core

AutoFixture is an open source library for .NET designed to minimize the 'Arrange' phase of your unit tests in order to maximize maintainability. Its primary goal is to allow developers to focus on what is being tested rather than how to setup the test scenario, by making it easier to create object graphs containing test data.

Highly performant and modular controls for node-based editors designed for data-binding and MVVM.

The mobile app vault (iOS and Android).

ASP.NET Core is a cross-platform .NET framework for building modern cloud-based web applications on Windows, Mac, or Linux.

Powerful .NET library for benchmarking

Build Mobile, Desktop and WebAssembly apps with C# and XAML. Today. Open source and professionally supported.

xUnit.net is a free, open source, community-focused unit testing tool for .NET.

EF Core is a modern object-database mapper for .NET. It supports LINQ queries, change tracking, updates, and schema migrations.

ML.NET is an open source and cross-platform machine learning framework for .NET.

.NET core API Gateway

Mono open source ECMA CLI, C# and .NET implementation.

Accept Bitcoin payments. Free, open-source & self-hosted, Bitcoin payment processor.

💫 NClient is an automatic type-safe .Net HTTP client that allows you to call web service API methods using annotated interfaces or controllers without boilerplate code.

Google's Material Design in XAML & WPF, for C# & VB.Net.

The best C# command line parser that brings standardized *nix getopt style, for .NET. Includes F# support

Linq to database provider.

:cake: Cake (C# Make) is a cross platform build automation system.