This fork evolved into a project that was developed in closed source by Robotec.ai for a while, before being released into open source again under Apache 2.0 in August 2021. Please see https://github.com/RobotecAI/ros2-for-unity if you are interested primarly in Unity3D integration with ros2, and https://github.com/RobotecAI/ros2cs if you want other applications / use cases for C# ros2 implementation.