# Storyyeller/Krakatau

Java decompiler, assembler, and disassembler

Repository: https://github.com/Storyyeller/Krakatau
Canonical: https://ross.abutalabs.com/products/krakatau
Language: Rust
License: GPL-3.0
License Family: copyleft
Last push: 2026-04-07T03:40:10+00:00

## Health v2 (maintenance only)
Score: 66/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 76, release rhythm 35, longevity 100
- inputs: {"age_days": 5066, "days_push": 148, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2244, forks 239 (observed 2026-08-28T04:06:30.008789+00:00)

## What it is
Krakatau is a Rust-based CLI tool for assembling, disassembling, and decompiling Java bytecode. It is specifically designed to handle obfuscated classfiles that break other tools, and its disassembled output can be reassembled back into classfiles.

## Use cases
- decompile obfuscated java jars
- disassemble java classfiles to readable text
- reassemble modified java bytecode
- write java classfiles from scratch in assembly
- analyze low-level details of java binaries
- reverse engineer obfuscated java code

## When to choose
- working with obfuscated or non-standard Java bytecode
- needing a roundtrip disassemble/reassemble workflow
- analyzing older Java code (pre-Java 8 features like lambdas unsupported in decompiler)

## When to avoid
- decompiling modern Java 8+ code relying on lambdas or newer language features
- wanting a GUI-based reverse engineering tool

## Facets
- artifact type: cli-tool
- maturity: active
- function: compiler, parser, reverse-engineering, developer-tools
- domain: developer-tools, reverse-engineering, security, programming-languages
- platform: cli, cross-platform, rust
- tags: java-bytecode, decompiler, disassembler, assembler, jvm, obfuscated-code, classfile

## Member repositories
- Storyyeller/Krakatau (main) score 66

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:30.008789+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 2026-08-30T02:44:01.137945+00:00, confidence not recorded.
  - readme: https://github.com/Storyyeller/Krakatau (fetched 2026-08-28T04:06:30.008789+00:00, sha 326d43c5725a)
- Data as of 2026-08-30T08:39:29.467469+00:00.