Algorithm and data structure articles for https://cp-algorithms.com (based on http://e-maxx.ru)
A free collection of curated, high-quality resources to take you from Bronze to Platinum and beyond.
C++ library to develop competitive programming problems
The IDE for competitive programming :tada: | Fetch, Code, Compile, Run, Check, Submit :rocket:
A modern open-source online judge and contest platform system.
Contest Management System
为了 OI 比赛而生的基于 Lemon + LemonPlus 的轻量评测系统 | 三大桌面系统支持
DOMjudge programming contest jury system
Self-calculated rating of problems in leetcode weekly/biweekly contests.
USACO 2026 Second Contest: Bronze, Silver and Gold problems explained, with verified C++17 solutions.
OJ Insight is a local-first competitive programming training workspace for multi-OJ analytics, ICPC/CCPC tracking, problem sets, virtual contests, personalized training, and post-contest review.