Top 4 xamarin-studio open source projects

Prism is a framework for building loosely coupled, maintainable, and testable XAML applications in WPF, Xamarin Forms, and Uno / Win UI Applications..

Xamarin Studio & Visual Studio for Mac add-in to open xib and storyboard files with Xcode Interface Builder by default

.NET Core support for MonoDevelop and Xamarin Studio

HoneyBees is a colorful, but easy-to-read, dark syntax highlighting theme for Microsoft Visual Studio for Mac & Xamarin Studio. It supports C#, XAML, XML, HTML, and CSS.