A utility to give some insight into how you use your keyboard
Convert code from C# to VB.NET and vice versa using Roslyn
Debugger libraries
MarkPad - a visual Markdown editor (inspired by the Downmarker project)
MonoDevelop is a cross platform .NET IDE
OmniSharp server (HTTP, STDIO) based on Roslyn workspaces
A cross-platform C# editor based on Roslyn and AvalonEdit
#ziplib is a Zip, GZip, Tar and BZip2 library written entirely in C# for the .NET platform.