Calendso (Legacy/Split)

Calendso was an open-source appointment scheduling platform designed to provide a customizable alternative to proprietary services. It gained significant traction for its 'open-core' model before rebranding to Cal.com in 2021.

Brand Authority Index (BAI): 18/100

Archetype: Phantom

Category: Software

https://optimly.ai/brand/calendso-legacy-split

Last analyzed: April 9, 2026

Verified from Calendso (Legacy/Split) website

Founded: 2021

Headquarters: Remote / USA (as Cal.com, Inc.)

Competitors

AI-Suggested Alternatives

Calendly

Buyer Intent Signals for Calendso (Legacy/Split)

Problems this brand solves

Manual Email Back-and-forth: Managing appointments via back-and-forth emails and manual calendar entries.
Spreadsheets/Shared Docs: Using generic spreadsheets or shared documents to track availability.
Virtual Assistant Agency: Hiring a virtual assistant to handle scheduling and administrative tasks.

Buyers search for

open source scheduling software
calendly alternatives open source
what happened to calendso
best self-hosted calendar app
scheduling tool for developers
Calendly: Relying on the established market leader for scheduling automation.