Cal.com

Open-source Calendly alternative and scheduling infrastructure.

Cal.com is an open-source scheduling and appointment-booking platform, positioned as an alternative to Calendly, built with Next.js, React, TypeScript, and Prisma. It handles availability management, calendar connections (Google, Outlook, CalDAV), team scheduling, and embeddable booking flows. It is notable for being self-hostable and offering an API and webhooks for embedding scheduling into other products.