# vmt/udis86

Disassembler Library for x86 and x86-64

Repository: https://github.com/vmt/udis86
Canonical: https://ross.abutalabs.com/products/udis86
Homepage: http://udis86.sourceforge.net
Language: C
License: BSD-2-Clause
License Family: permissive
Last push: 2023-05-10T01:14:38+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 5293, "days_push": 1212, "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 1080, forks 316 (observed 2026-08-28T04:03:30.586566+00:00)

## What it is
Udis86 is a C library (libudis86) for disassembling x86 and x86-64 machine code, decoding raw binary streams into structured instructions with Intel or AT&T syntax output. It also ships udcli, a small command-line tool for quick disassembly from files, memory buffers, or stdin.

## Use cases
- disassemble x86-64 machine code into assembly
- decode raw binary instruction streams in C
- analyze binary code for reverse engineering
- disassemble shellcode or memory buffers
- convert hex bytes to assembly from the command line
- build binary analysis or debugging tools

## When to choose
- you need a lightweight, re-entrant C library for x86/x86-64 disassembly
- you want both Intel and AT&T syntax output
- you need no dynamic memory allocation and a documented API
- you want a quick CLI disassembler for hex dumps

## When to avoid
- you need disassembly for non-x86 architectures like ARM or RISC-V
- you need actively maintained support for the newest AVX-512 or APX instruction extensions
- you want a higher-level analysis framework like a full decompiler

## Facets
- artifact type: library
- maturity: maintenance
- function: parser, developer-tools, reverse-engineering
- domain: developer-tools, security, operating-systems
- platform: windows, cross-platform, cli, c
- tags: disassembler, x86, x86-64, binary-analysis, reverse-engineering, assembly, libudis86, udcli, linux, macos

## Member repositories
- vmt/udis86 (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:30.586566+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 2026-08-30T06:53:00.991971+00:00, confidence not recorded.
  - readme: https://github.com/vmt/udis86 (fetched 2026-08-28T04:03:30.586566+00:00, sha e44f542d0a3f)
  - homepage: http://udis86.sourceforge.net (fetched 2026-08-29T12:53:54.316046+00:00, sha 0366171f2cf7)
  - site_page: https://sourceforge.net/about (fetched 2026-08-29T12:53:54.325398+00:00, sha 47a5f3730d75)
  - site_page: https://sourceforge.net/p/forge/documentation/Docs%20Home (fetched 2026-08-29T12:53:54.327538+00:00, sha 3cca19403dfa)
  - site_page: https://sourceforge.net/about/project_awards (fetched 2026-08-29T12:53:54.329320+00:00, sha f5906d81e063)
  - site_page: https://sourceforge.net/about/leadership (fetched 2026-08-29T12:53:54.330954+00:00, sha bfffa8fdd816)
- Data as of 2026-08-30T08:39:29.467469+00:00.