# Frege/frege

Frege is a Haskell for the JVM. It brings purely functional programing to the Java platform.

Repository: https://github.com/Frege/frege
Canonical: https://ross.abutalabs.com/products/frege
Homepage: https://github.com/Frege/frege/wiki/_pages
Language: Frege
License: NOASSERTION
License Family: other
Last push: 2026-07-11T08:33:45+00:00

## Health v2 (maintenance only)
Score: 64/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 92, release rhythm 8, longevity 100
- inputs: {"age_days": 5088, "days_push": 53, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- 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 3713, forks 148 (observed 2026-08-28T04:08:15.261781+00:00)

## What it is
Frege is a purely functional programming language for the JVM that is essentially Haskell, featuring a strong static type system with global type inference and lazy evaluation. It compiles to Java bytecode and source, allowing seamless interoperability with any Java library and embedding in Java projects.

## Use cases
- write haskell-style code on the jvm
- call functional code from java projects
- learn purely functional programming with type inference
- use java libraries from a haskell-like language
- compile functional code to java bytecode
- try a haskell dialect in an online repl

## When to choose
- you want Haskell semantics but must target the JVM
- you need pure functional code interoperable with Java
- you value strong static typing with purity tracking in the type system

## When to avoid
- you need the full GHC ecosystem and its native libraries
- your team is not familiar with functional programming
- you need a language with a large active community and frequent updates

## Facets
- artifact type: library
- maturity: maintenance
- function: compiler, interpreter, type-system, programming-language
- domain: programming-languages, compilers
- platform: jvm, cross-platform
- tags: haskell, jvm-language, purely-functional, lazy-evaluation, type-inference, java-interop, functional-programming

## Member repositories
- Frege/frege (main) score 64

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:15.261781+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 2026-08-29T18:30:52.495840+00:00, confidence not recorded.
  - readme: https://github.com/Frege/frege (fetched 2026-08-28T04:08:15.261781+00:00, sha ca970d204797)
  - homepage: https://github.com/Frege/frege/wiki/_pages (fetched 2026-08-29T09:24:13.876405+00:00, sha 6a42d8d10357)
- Data as of 2026-08-30T08:39:29.467469+00:00.