Because implementing obsolete programming languages is a great use of my free time, I've created cxxforth, an implementation of Forth in C++.
Inspired by JONESFORTH, I wrote it in the style of a tutorial. The source code is automatically converted to a pretty-printed format: https://github.com/kristopherjohnson/cxxforth/blob/master/cxxforth.cpp.md.
Now, on to the next waste of my time...