# janino-compiler/janino

Janino is a super-small, super-fast Java™ compiler.

Repository: https://github.com/janino-compiler/janino
Canonical: https://ross.abutalabs.com/products/janino
Homepage: http://janino-compiler.github.io/janino
Language: Java
License: NOASSERTION
License Family: other
Topics: compiler, java-compiler, in-memory-java-compiler, janino
Archived: true
Last push: 2026-07-04T07:43:33+00:00

## Health v2 (maintenance only)
Score: 10/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 90, release rhythm 8, longevity 100
- inputs: {"age_days": 3734, "days_push": 60, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: archived, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1326, forks 213 (observed 2026-08-28T04:04:22.801737+00:00)

## What it is
Janino is a super-small, super-fast Java compiler that can compile source files to class files like javac, or compile Java expressions, blocks, class bodies, or .java files in memory and execute them directly in the running JVM. It integrates with Apache Commons JCI and Drools and can also be used for static code analysis and code manipulation.

## Use cases
- evaluate java expressions at runtime
- compile java code in memory
- embed a scripting engine in a jvm application
- compile java snippets dynamically in drools rules
- run a lightweight java compiler without full javac
- analyze or manipulate java source code programmatically

## When to choose
- you need fast, lightweight in-memory compilation of Java expressions, blocks, or classes inside a running JVM
- you want runtime scripting/evaluation capabilities in a Java application
- you need a small compiler dependency for tools like Drools or Apache Commons JCI

## When to avoid
- you need full javac feature coverage, latest Java language features, or long-term support, since the project was archived in 2025
- you need an actively maintained compiler with bug fixes and new JDK compatibility
- you need ahead-of-time compilation of large codebases where a full toolchain is better suited

## Facets
- artifact type: library
- maturity: maintenance
- function: compiler, interpreter, parser
- domain: compilers, programming-languages, developer-tools
- platform: jvm, cli
- tags: in-memory-compilation, java-compiler, runtime-code-evaluation, expression-evaluator, scripting

## Member repositories
- janino-compiler/janino (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:22.801737+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 2026-08-30T04:46:22.429035+00:00, confidence not recorded.
  - readme: https://github.com/janino-compiler/janino (fetched 2026-08-28T04:04:22.801737+00:00, sha 94bae99801fd)
  - homepage: http://janino-compiler.github.io/janino (fetched 2026-08-29T12:05:14.883561+00:00, sha 13592d18fd62)
- Data as of 2026-08-30T08:39:29.467469+00:00.