C# Programming Resources

Open Source Apps

Paint.NET - It's no longer open source as the author seems to be annoyed! But a wonderful C# paint program nevertheless.
ShareX/ShareX - ShareX is a free and open source program that lets you capture or record any area of your screen.

Libraries and Drivers

Packaging and Installation

nuget - The official .NET package manager.
.NET Core - The absolutely free and open source (FOSS) version of .NET which is developed independently of Microsoft Windows platform.
monodevelop - The platform independent .NET IDE, supports CLR languages like C#, VB.NET, etc.