lemonlime

A lightweight judging system built for Olympiad‑style programming contests, extending the Lemon and LemonPlus platforms. It runs on Linux, Windows, and macOS and requires Qt 6.8 or newer. The interface lets organizers define four problem types—traditional, answer‑only, interactive, and communication—while supporting per‑submission re‑testing, customizable maximum re‑judge counts, and detailed numeric comparison that checks both absolute and relative errors, handling special values such as nan and inf.

The tool offers fine‑grained control over test points, including sub‑task dependencies and an enhanced test‑point editor, as well as statistical summaries of contest scores. Features such as multi‑threaded evaluation (experimental), high‑DPI support, color‑coded result displays, and theme customization for IOI and JOI styles improve usability. Users can rename contests, reorder problems, and manage source files both inside and outside participant folders, with automatic backup and cleanup utilities.

Installation is provided via pre‑built packages for each supported platform, including Homebrew Cask for macOS, DEB packages for Debian/Ubuntu, AUR for Arch Linux, and static binaries for any system. Documentation is available both offline within the application and online.