# DMOJ/online-judge

A modern open-source online judge and contest platform system.

Repository: https://github.com/DMOJ/online-judge
Canonical: https://ross.abutalabs.com/products/online-judge
Homepage: https://dmoj.ca
Language: Python
License: AGPL-3.0
License Family: copyleft
Topics: python, dmoj, dmoj-judge, programming-contests, programming-challenge, coding-interviews, coding-competitions, online-judge
Last push: 2026-08-25T00:49:46+00:00

## Health v2 (maintenance only)
Score: 67/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 8, longevity 100
- inputs: {"age_days": 4557, "days_push": 9, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1182, forks 451 (observed 2026-08-28T04:03:54.322345+00:00)

## What it is
DMOJ is a modern open-source online judge and contest platform for hosting programming competitions and practice problems. It supports sandboxed judging in over 60 language runtimes, multiple contest formats, Elo-style rating, and rich problem statements with LaTeX and PDF export.

## Use cases
- host a competitive programming contest
- run a coding practice site for students
- set up a self-hosted online judge
- grade programming submissions automatically
- organize national olympiad informatics competitions
- track coder ratings with Elo-style ranking
- create programming problems with LaTeX statements

## When to choose
- you need a battle-tested judge that has hosted national olympiads
- you want support for interactive and signature-graded tasks
- you need many contest formats like ICPC, IOI, or AtCoder out of the box
- you require judging in dozens of programming languages with per-language limits

## When to avoid
- you only need a simple quiz or multiple-choice assessment tool
- you want a lightweight single-page coding playground without user accounts
- you cannot operate the separate judge-server component and its sandboxing requirements
- you need a commercial turnkey product with vendor support

## Facets
- artifact type: application
- maturity: active
- function: web-framework, api-framework, auth, authorization, search-engine, data-visualization, documentation, markdown, pdf, email, developer-tools
- domain: education, web-development, programming-languages, self-hosted, gaming-tools
- platform: python, self-hosted
- tags: online-judge, competitive-programming, contests, code-grading, judge-server, django, rating-system, plagiarism-detection, algorithms, web-server, docker, linux

## Member repositories
- DMOJ/online-judge (main) score 67

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:54.322345+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 2026-08-30T06:24:45.496375+00:00, confidence not recorded.
  - readme: https://github.com/DMOJ/online-judge (fetched 2026-08-28T04:03:54.322345+00:00, sha e1e99a938651)
- Data as of 2026-08-30T08:39:29.467469+00:00.