C# is a programming language. The following is a list of software programmed in it:
- Banshee, a cross-platform open-source media player.
- Beagle, a search system for Linux and other Unix-like systems.
- Colectica, a suite of programs for use in managing official statistics and statistical surveys using open standards.
- Chocolatey, an open source package manager for Windows.
- Docky, a free and open-source application launcher for Linux.
- FlashDevelop, an integrated development environment (IDE) for development of Adobe Flash websites, web applications, desktop applications and video games.
- GameMaker Studio 2, a game engine with an editor written in C#
- HandBrake, a free and open-source transcoder for digital video files.
- KeePass, a free and open-source password manager primarily for Windows.
- Low Orbit Ion Cannon (LOIC), an open-source network stress testing and denial-of-service attack application.
- Lphant, a peer-to-peer file sharing client.
- MonoDevelop, an open source integrated development environment.
- NMath, a numerical package for the Microsoft .NET Framework.
- Open Dental, a dental practice management software.
- OpenRA, a free remake of the classic Command & Conquer game.
- osu!, a free and open-source (before freeware) Indie rhythm game with 4 modes for Microsoft Windows, Linux and macOS.
- Paint.NET, a freeware raster graphics editor program for Microsoft Windows, developed on the .NET Framework..
- Pinta, an open-source, cross-platform bitmap image drawing and editing program.
- SharpDevelop, a free and open source integrated development environment (IDE) for the .NET Framework.
- Windows Installer XML (WiX), a free software toolset that builds Windows Installer packages from XML.
- WorldWide Telescope, an astronomical data visualization tool.