An online judge is an online system to test programs in programming contests. They are also used to practice for such contests like ICPC. The system can compile and execute your code, and test your code with pre-constructed data. Submitted code may be run with restrictions, including time limit, memory limit, security restriction, and so on. The output of the code will be captured by the system, and compared with the standard output. The system will then return the result.
Hydro - Next generation high performance online-judge platform - 新一代高效强大的信息学在线测评系统 (a.k.a. vj5)
Robust, fast, scalable, and sandboxed open-source online code execution system for humans and AI.
A modern open-source online judge and contest platform system.
✨ Simple, free and open-source online code editor.
Judging backend server for the DMOJ online judge.
⚡ The most advanced open-source automatic algorithm online judge system | 南京邮电大学开源 Online Judge | QQ群：668108264
The problem data (Test case generator, judge's solution, task, ...) of Library Checker
A cross-platform online judge system based on Spring framework and ActiveMQ.
The online judge service with millions of submissions, since 2005.
PAT OJ exercises in C language 浙江大学PAT纯C语言题解。
High-Performance Data Generator for competitive programming (Olympiad in Informatics) use.
浙江大学PAT题解 https://pintia.cn
Jiangnan Online Judge
An open source online judge system base on Django REST framework and Vue.js !
A modern open-source online judge and contest platform system.
A full-stack online coding platform powered by Spring Cloud microservices and a Vue 3 frontend, offering scalable, secure, and interactive coding challenges.
洛谷风格在线评测系统 | Django + Bootstrap5 开发。支持用户系统、题目库、多语言代码提交（C/C++/Python/Java）、提交记录、排行榜及管理后台。轻量级 OJ，适合编程练习与竞赛训练。Luogu-style Online Judge built with Django & Bootstrap5. Features: user auth, problem set with difficulty tiers, multi-language code submissions (C/C++/Python/Java), submission logs, leaderboard, and admin panel.