A Simple, incomplete LISP implementation (header only, C++11).
Will need closures/lambdas and a few standard calls to start working as a general purpose language
Let's say the license is GPL, okay?
http://cse.csusb.edu/dick/samples/lisp.semantics.txt https://code.google.com/p/atom/source/browse/trunk/libatom/Functions.cpp http://howtowriteaprogram.blogspot.cz/2010/11/lisp-interpreter-in-90-lines-of-c.html