QuantConnect
Lean Algorithmic Trading Engine by QuantConnect (Python, C#)
dotnet
EF Core is a modern object-database mapper for .NET. It supports LINQ queries, change tracking, updates, and schema migrations.
StockSharp
Algorithmic trading and quantitative trading open source platform to develop trading robots (stock markets, forex, crypto, bitcoins, and options).
OrchardCMS
Orchard Core is an open-source modular and multi-tenant application framework built with ASP.NET Core, and a content management system (CMS) built on top of that framework.
ChilliCream
Welcome to the home of the Hot Chocolate GraphQL server for .NET, the Strawberry Shake GraphQL client for .NET and Nitro the awesome Monaco based GraphQL IDE.
smartstore
Open Source ASP.NET MVC Enterprise eCommerce Shopping Cart Solution
nunit
NUnit Framework
helix-toolkit
Helix Toolkit is a collection of 3D components for .NET.
YAFNET
🌐 YAF.NET - C# ASP.NET Forum