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

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

Powerful .NET library for benchmarking

Command line parsing, invocation, and rendering of terminal output.

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

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.

Headless Chrome .NET API

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

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

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

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

🦄 .NET orm, Mysql orm, Postgresql orm, SqlServer orm, Oracle orm, Sqlite orm, Firebird orm, 达梦 orm, 人大金仓 orm, 神通 orm, 翰高 orm, 华为GaussDB orm, MsAccess orm.

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

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

Open source, headless, multi-tenant eCommerce platform built with .NET Core, MongoDB, AWS DocumentDB, Azure CosmosDB, Vue.js.

MonoDevelop is a cross platform .NET IDE

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

Linq to database provider.

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

High performance and modular controls for node based editors designed for databinding and MVVM.

An open source fork of Windows Live Writer

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

Python for .NET is a package that gives Python programmers nearly seamless integration with the .NET Common Language Runtime (CLR) and provides a powerful application scripting tool for .NET developers.

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

One framework for creating powerful cross-platform games.

A cross-platform plotting library for .NET

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

.NET core API Gateway