I've released a new open-source project for Revit C# developers called Bowerbird. It uses the Roslyn C# compiler to allow users to create and edit new commands directly from C# source files, without having to go through the process of creating and deploying a plug-in, and re-launching Revit.
It is inspired by pyRevit by Ehsan Iran-Nejad and Revit.ScriptCS by Sridhar Baldava.
I'd greatly appreciate any feedback or contributions at https://github.com/ara3d/bowerbird/
Thanks in advance!