Mono is described as 'Free and open source project led by Xamarin (formerly by Novell and originally by Ximian) to create an Ecma standard compliant .NET Framework-compatible set of tools including, among others, a C# compiler and a Common Language Runtime' and is a software framework in the development category. There are seven alternatives to Mono for a variety of platforms, including Windows, Linux, Mac, Web-based and BSD apps. The best Mono alternative is Qt, which is both free and Open Source. Other great apps like Mono are .NET Framework, .NET Core, .NET Micro Framework for Linux and Nevron Open Vision for .NET.