# koka-lang/koka

Koka language compiler and interpreter

Repository: https://github.com/koka-lang/koka
Canonical: https://ross.abutalabs.com/products/koka
Homepage: http://koka-lang.org
Language: Koka
License: NOASSERTION
License Family: other
Topics: algebraic-effects, koka, handler, haskell, effect-handlers
Last push: 2026-08-15T16:25:40+00:00

## Health v2 (maintenance only)
Score: 90/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 97, release rhythm 75, longevity 100
- inputs: {"age_days": 3555, "days_push": 18, "days_rel": 169, "gap_med": 13, "n_releases_24m": 4}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4046, forks 219 (observed 2026-08-28T04:08:33.601275+00:00)

## What it is
Koka is a strongly typed functional programming language with a polymorphic effect type system and algebraic effect handlers, developed as a research language. Its compiler and interpreter compile Koka programs directly to C without a garbage collector using the Perceus reference-counting method.

## Use cases
- experiment with algebraic effects and handlers
- learn a functional language with effect types
- compile functional programs to C without a GC runtime
- study advanced type systems and effect inference
- build async/await or exception abstractions as user libraries

## When to choose
- you want to explore or research effect handlers and effect typing
- you need precise control over memory via reference counting without a runtime
- you are doing programming-language research or teaching

## When to avoid
- you need a production-ready language with mature ecosystem and libraries
- you need guaranteed long-term stability for a commercial project
- your team requires mainstream tooling and hiring pool

## Facets
- artifact type: cli-tool
- maturity: experimental
- function: compiler, interpreter, programming-language, type-system
- domain: programming-languages, compilers
- platform: windows, cpp, cli
- tags: algebraic-effects, effect-handlers, functional-language, perceus, reference-counting, research-language, algorithms, linux, macos

## Member repositories
- koka-lang/koka (main) score 90

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:33.601275+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 2026-08-29T18:23:43.246451+00:00, confidence not recorded.
  - readme: https://github.com/koka-lang/koka (fetched 2026-08-28T04:08:33.601275+00:00, sha d09f935a34d3)
  - homepage: http://koka-lang.org (fetched 2026-08-29T09:16:06.130217+00:00, sha c0fd1829a3dc)
- Data as of 2026-08-30T08:39:29.467469+00:00.