SharpDevelop (#develop) is a free and open source integrated development environment (IDE) for the .NET Framework, Mono, Gtk#, Glade# platforms. Developed by IC#Code
License: Open Source
Xamarin Studio is a powerful IDE focused on cross-platform mobile app development with robust support for C# and rich UI design tools, while SharpDevelop is an open-source IDE that is lightweight and more suited for desktop application development. Xamarin Studio offers better integration with mobile platforms and Azure, whereas SharpDevelop is more flexible for various programming languages but lacks mobile-focused features.