TSI is originally based on the metacircular evaluator in SICP chapter 4, and it can run the metacircular evaluator. You can compare between tags to see how it grows.

Run interactive mode:

./main.py

Execute script:

./main.py script.scm

"Powerful Features":

• call/cc
• no stack overflow in recursion call

Missing:

• rational number
• quasiquote notation, # literals
• many primary procedures & some special forms