Mellivora Mellivora is a PHP-based Capture The Flag (CTF) engine designed to host cybersecurity competitions and challenges. The platform supports arbitrary categories and challenges, allowing organizers to create diverse security scenarios for participants. It includes a comprehensive scoreboard system that accommodates multiple team types and tracks participant progress throughout competitions. The engine provides manual or automatic marking capabilities for free-text submissions, enabling flexible challenge evaluation methods. Challenge management features include hint systems, time-based exposure limits, and progressive challenge reveals that unlock based on parent challenge completion. Administrative functionality encompasses user management with IP correlation tracking, signup restrictions using email regex patterns, and a dedicated management console for competition oversight. The platform integrates reCAPTCHA support for enhanced security and includes TOTP two-factor authentication for user accounts. File handling capabilities support challenge file uploads to local storage or Amazon S3, accommodating various challenge formats and requirements. The system includes configurable caching mechanisms and SMTP email support for participant communications. Team progress and overview pages provide participants with visibility into their advancement and performance metrics. The platform offers signup restrictions and user management tools to control competition access and maintain organized participant databases.