Kent Dybvig's Scheme Machine in 400 Lines of C (Heap-Memory Model)
In plain words
This is a compact Scheme interpreter written in approximately 400 lines of C, implementing a heap-memory model for managing runtime data. It interprets the Scheme programming language, a dialect of Lisp, and is designed for anyone interested in understanding how programming language implementations work at a fundamental level. The project demonstrates core interpreter concepts including memory management and expression evaluation within tight space constraints, making it useful for educational purposes or as a reference implementation.
written from the facts on this page · September 2026
Does the same job
all alternatives →- LWLisp with GC in 436 Bytes2021 · justine.lol · ▲513
- MMMicro-mitten – Research language with compile-time memory management2020 · github.com · ▲236
I've been working on implementing the compile-time approach to memory management described in this thesis (https://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-908.pdf) for some time now - some of the performance results look promising! (Although some less so...) I think it would be great to see this taken further and built into a more complete functional language.
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The book page links to a blog post that explains how I got about it (and has a link to sample content), but the TL&DR is that I could not find a lot of books that were on "our" history _and_ were larded with technical details. So I set about writing one, and some five years later I'm happy to share the result. I think it's one of the few "computer history" books that has tons of code, but correct me if I'm wrong (I wrote this both to tell a story and to learn :-)). My favorite languages are Smalltalk and Lisp, but as an Emacs user, I've been using the latter for much longer and for my…
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Long-simmering side project that is finally ready to see the light. HAMTs are a cool persistent data structure and implementing one has been a lot of fun. Beyond the code, there is likely some value in the extensive and largely complete implementation docs; basic benchmarks are linked in the README, too. Kind of aiming to be "the libavl for HAMTs". That is obviously a high and aspirational bar but a distinct possibility if it stirs up a little interest and/or contribution. Anyways, it's time for this to go out, collect feedback and maybe even some use outside of toy projects. Let me…
- YAYet another memory system for LLMs2025 · github.com · ▲165
Built this for my LLM workflows - needed searchable, persistent memory that wouldn't blow up storage costs. I also wanted to use it locally for my research. It's a content-addressed storage system with block-level deduplication (saves 30-40% on typical codebases). I have integrated the CLI tool into most of my workflows in Zed, Claude Code, and Cursor, and I provide the prompt I'm currently using in the repo. The project is in C++ and the build system is rough around the edges but is tested on macOS and Ubuntu 24.04.
- ACA compiler and VM for a simple language, in 150 lines of code2022 · gist.github.com · ▲200
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Launched alongside, October 2025
the whole month →
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