# janet-lang/janet

A dynamic language and bytecode vm

Repository: https://github.com/janet-lang/janet
Canonical: https://ross.abutalabs.com/products/janet
Homepage: https://janet-lang.org
Language: C
License: MIT
License Family: permissive
Topics: c, language, vm, lisp, macros, repl, interpreter, functional-language, imperative-language
Last push: 2026-08-26T22:15:31+00:00

## Health v2 (maintenance only)
Score: 85/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 59, longevity 100
- inputs: {"age_days": 3463, "days_push": 7, "days_rel": 196, "gap_med": 82.5, "n_releases_24m": 9}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4370, forks 274 (observed 2026-08-28T04:08:46.730288+00:00)

## What it is
Janet is a dynamic functional and imperative Lisp-like programming language with its own bytecode VM, implemented in a single embeddable C source file. It ships with a REPL, interpreter, compiler, and rich core library including threads, networking, an event loop, and PEG parsing.

## Use cases
- system scripting
- embed a scripting language in a C or C++ application
- rapid prototyping with a dynamic language
- write automation scripts with built-in networking and event loop
- export standalone executables from scripts
- learn a small Lisp with macros and REPL

## When to choose
- you want an embeddable scripting language smaller and easier to port than Lua alternatives with more batteries included
- you need a lightweight single-binary language for system scripting
- you want direct C interop and dynamic library loading
- you need built-in threads, green threads, and an event loop out of the box

## When to avoid
- you need a large ecosystem of third-party libraries like Python's
- you require heavy static typing or compile-time safety guarantees
- your team depends on mainstream language tooling and hiring pools
- you need high-performance numeric computing with mature GPU or array ecosystems

## Facets
- artifact type: cli-tool
- maturity: stable
- function: interpreter, programming-language, cli, concurrency, networking
- domain: programming-languages, developer-tools
- platform: windows, bsd, cross-platform, cli, c
- tags: lisp, bytecode-vm, embeddable, macros, repl, peg-parsing, functional-language, scripting-language, c-interop, command-line, automation, linux, macos

## Member repositories
- janet-lang/janet (main) score 85

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:46.730288+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:21:22.669481+00:00, confidence not recorded.
  - readme: https://github.com/janet-lang/janet (fetched 2026-08-28T04:08:46.730288+00:00, sha 952b865203aa)
  - homepage: https://janet-lang.org (fetched 2026-08-29T09:09:45.403635+00:00, sha 032d5cb3834a)
  - site_page: https://janet-lang.org/docs/index.html (fetched 2026-08-29T09:09:45.422701+00:00, sha 4dabc3c46340)
- Data as of 2026-08-30T08:39:29.467469+00:00.