JWithATwist is a programming language under development. It has many similarities with the programming language J. You can look at www.jsoftware.com to find out what J is.
You can download JWithATwist here.
You can clone the JWithATwist repository and use JWithATwist from Visual Studio.
You can find the JWithATwist documentation here.
You can find information about some design decisions in this blog - erlhelinfotech.wordpress.com.
The tests are also documentation.