Cal.com

Cal.com is the open-source scheduling infrastructure platform built as a developer-first alternative to Calendly. What makes Cal.com different for custom web application development is that you can self-host the entire scheduling engine on your own infrastructure, giving you complete control over your data, branding, and customization. The platform provides a robust API, webhook support, and embeddable booking widgets that integrate seamlessly into any application. For developers building client portals, internal tools, or marketplace platforms, Cal.com offers the flexibility to customize every aspect of the scheduling experience without being locked into a proprietary vendor.

The Origin Story

Cal.com was founded in 2021 by Peer Richelsen, a German-born designer and developer who was frustrated with the limitations of existing scheduling tools. Richelsen had been working on a scheduling project called Calendso, which he open-sourced on GitHub. The project quickly gained traction in the developer community, accumulating thousands of GitHub stars in its first few months. Recognizing the opportunity, Richelsen rebranded the project to Cal.com and raised seed funding to build a company around the open-source core. The company secured the premium domain cal.com and positioned itself as the open-source scheduling layer for the internet.

Why Developers Love It

Cal.com acquired the domain name cal.com through a deal that reportedly cost a significant six-figure sum, making it one of the most expensive three-letter .com domains purchased by a startup at such an early stage. The decision to invest heavily in the domain before the company had substantial revenue was a deliberate bet that a short, memorable domain would become a competitive advantage as the product scaled. Richelsen has talked about how the domain purchase was one of the most debated decisions in the company's early history.

Visit: cal.com