Calysto Scheme is a sophisticated Scheme interpreter implemented in Python that integrates with Jupyter notebooks. It features a multi-stage compilation pipeline (CPS → DS → RM → Python) with JIT compilation, continuation support (call/cc), and seamless Python interoperability. The system includes advanced optimizations like persistent vectors for O(1) lexical address lookup, epoch-based cache invalidation, and escape analysis for JIT inlining. It's used in educational contexts and provides debugging tools like a stepper-debugger, making it both a practical development tool and a platform for teaching programming language concepts.
Rivulet is an interpreter for an esoteric programming language of the same name, where code is written using semigraphic characters that form flowing strands. The system parses these visual programs into executable glyphs, interprets them according to unique semantics involving lists, strands, and conditional rollbacks, and can output results as text, numbers, or SVG visualizations. The architecture separates parsing, interpretation, and visualization concerns into distinct modules. While primarily a language implementation, the SVG generator demonstrates reusable visualization techniques.