Cal.com is one of the most-cited "open-source Calendly alternative" SaaS products of the past few years, founded in 2021 by Peer Richelsen (German) and Bailey Pumfleet (UK), with the commercial entity incorporated as Cal.com, Inc. in San Francisco, California despite the EU-founder origin. The company has raised approximately US$32M in venture funding and the GitHub repository (calcom/cal.com) has accumulated more than 41,000 stars since launch. The product replaces Calendly's hosted scheduling experience with a self-hostable, AGPLv3-licensed open-source codebase plus a managed SaaS (cal.com), a model that was the directory's reference "EU founders bringing US-style SaaS open-source pressure" story until 2026.
The 2026 strategic shift complicates the listing. Per public reporting and direct corporate communication, Cal.com is moving its production codebase behind closed doors during 2026, leaving only a stripped community edition called Cal.diy under the more-permissive MIT licence, while rewritten authentication, data-handling, and commercial systems become proprietary. This narrows the structural "fork-if-anything-changes" guarantee that historically distinguished Cal.com from Calendly. For procurement-grade EU buyers the picture is now: (a) the hosted Cal.com SaaS is US-incorporated under Cal.com, Inc. and subject to US extraterritorial law by default, direct CLOUD Act exposure under our strict-ownership stance; (b) the privacy policy explicitly confirms data transfers to the United States, with US sub-processors Stripe, Twilio, and Daily.co alongside PostHog (UK); (c) the Cal.diy MIT community edition on EU infrastructure (Hetzner, OVHcloud, Scaleway) remains a legitimate self-host option but with reduced feature parity vs the proprietary hosted product.
Pricing for the hosted SaaS is freemium with paid Team and Enterprise tiers; specific entry-tier EUR figures were not captured at audit. Best fit: developers and product builders who specifically want the Cal.com API surface and accept US-incorporation; teams comfortable with the new MIT/Cal.diy self-host path on EU infrastructure for sovereignty. Procurement-grade EU-only buyers needing a structurally EU-incorporated alternative should choose Doodle (CH, TX Group), SuperSaaS (NL, founder-owned), or Reservio (CZ, ABUGO Group) instead; all listed elsewhere in this category.