MOJthe MAPS Online Judge

An online judge and contest platform written in TypeScript, compatible with DMOJ. All DMOJ URLs work, the problem format is unchanged, and an existing site imports.

Installation

Compatibility with DMOJ

Problem format

Runs the DMOJ judge

The grader is the DMOJ judge-server, carried as a git subtree. Problem data written for DMOJ grades unchanged.

Imports an existing DMOJ site

Users, password hashes, TOTP secrets, passkeys, problems, submissions, contests, ratings and comments come across from a MariaDB dump.

Live without polling

Submission status, contest rankings and judge status are reactive queries. There is no event daemon.

Contest formats from DMOJ

Default, IOI, legacy IOI, AtCoder, ICPC and ECOO, plus scoreboard freeze, blind mode and a reveal ceremony.

Judges anywhere

A judge polls the site over HTTPS, so it needs no inbound port, no static address and no VPN.

Rebrandable without a deploy

Name, wordmark, favicon, colours, default theme and custom CSS are settings in the staff console.

The MOJ home page

Where to start

Installation — run MOJ on your own machine.
Production — run it on a server, behind TLS.
Compatibility with DMOJ — what is the same, what imports, what differs.
Problem format — init.yml, statements and config.json.
Importing from DMOJ — move an existing site across.

MOJ is maintained by MAPS, Monash Algorithms and Problem Solving, and is free software under the AGPL-3.0.