The Shadow Framework is, basically, a set of software tools to work with Curved Polygons Net on top of Standard Graphics APIs, like OpenGL or Vulkan. For this reason, it make sense to release it in many languages, with the support of addictional libraries to target specific platforms.
A C# version for Unity is on Development and is going to be released on summer 2019. Together with the core features of the framework, it will count a Unity integration (named Curved Poly - Runtime and actually part of Curved Poly)
Together with the C#, I'm going to release also a javascript version based on WebGL, on summer 2019. With the WebGL/Javascript version you will be able to encapsulate 3D contents directly on your web pages. I'm also planning to release a Trhee Js wrapper to ease the integration with it.
Originally, the Shadow Framework was designed as a research project written in Java with the Java OpenGL extension. As years went by, I also released a Java version for Android (at the time I was running a few Android Projects with some students). And updated Java version will be released most likely next autumn, since I'm giving priority to Unity and WebGL.
There is also a C++ version of the framework which has never been released (mainly because it has never been fully aligned with the java one). For instance, I used a Shadow Framework 2.0 C++ porting on iOS on 2014 on one of my projects; it was mainly a C++ version with some platform-specific Objective C component. Version 4.0 will sure feature a C++ version, which i plan to release on autumn 2019; for now, i'm not planning to release any platform specific code soon, but a comprehensive documentation which will help you to integrate the C++ core in your projects.