Cal.com

Cal.com is scheduling infrastructure for booking appointments: it publishes booking links, checks connected calendars for free slots, and writes confirmed events back with time zone detection and reminders. Event types, round robin and collective team scheduling, routing forms, and workflow automation cover far more than a simple personal calendar page.

Sales teams route inbound leads to the right representative, while clinics, coaches, and service businesses run recurring bookings and follow-up sequences through it.

Self-hosting keeps customer schedules and meeting metadata off third-party servers, without per-booking or per-seat billing.