Cal.diy emerges as a fully open-source scheduling platform, forked from Cal.com with all enterprise features removed. Designed for individuals and self-hosters, Cal.diy offers complete control over scheduling infrastructure without commercial dependencies. The project is 100% MIT-licensed and community-maintained, making it ideal for developers who want to run their own scheduling system.

Unlike the commercial Cal.com platform, Cal.diy excludes enterprise features like Teams, Organizations, Insights, Workflows, and SSO/SAML. There's no license key required, and the entire codebase remains open source with no "Open Core" split. The platform is built with modern technologies including Next.js, React.js, Tailwind CSS, and Prisma.io, providing a robust foundation for self-hosted scheduling needs.

Setting up Cal.diy requires advanced server administration skills, as users must handle their own database management and security. The project provides detailed installation instructions for PostgreSQL, environment configuration, and development setup. While not suitable for production use without proper expertise, Cal.diy represents a significant option for privacy-conscious users and developers seeking complete control over their scheduling infrastructure without vendor lock-in.