This is a naïve interpreted Scheme implemented in C#. John wrote it as a learning project. Main things I learned were that

• you really can write a functioning Scheme interpreter by porting the Wizard Book's metacircular evaluator to the language of your choice,

• call/cc is easy if you write your underlying interpreter in CPS, and

• the whole thing is easier than it looks. I was able to get the entire thing (including call/cc working in handful of hours, having never implemented a language since school).

This is not a complete Scheme, but it handles a subset of the language correctly and exercises some core ideas like continuations and syntactic transformations. Randy added a bignum implementation so we have a subset of real R5RS arithmetic. Cool!