# 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.
- URL: https://optimly.ai/brand/calendso-legacy-split
- Slug: calendso-legacy-split
- BAI Score: 18/100
- Archetype: Phantom
- Category: Software
- Last Analyzed: April 9, 2026
## Competitors
- Acuity Scheduling (https://optimly.ai/brand/acuity-scheduling)
- Calendly (https://optimly.ai/brand/calendly)
- Easyappointments (https://optimly.ai/brand/easyappointments)
## AI-Suggested Alternatives
- Calendly (https://optimly.ai/brand/calendly)
## Buyer Intent Signals
Problems: 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.
Solutions: 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.
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## Full Details / RAG Data
### Overview
Calendso (Legacy/Split) is listed in the AI Directory.
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.
### Metadata
| Field        | Value |
|--------------|-------|
| Name         | Calendso (Legacy/Split) |
| Slug         | calendso-legacy-split |
| URL          | https://optimly.ai/brand/calendso-legacy-split |
| BAI Score    | 18/100 |
| Archetype    | Phantom |
| Category     | Software |
| Last Analyzed | April 9, 2026 |
| Last Updated | 2026-04-13T15:39:22.129Z |
### Verified Facts
- Founded: 2021
- Headquarters: Remote / USA (as Cal.com, Inc.)
### Competitors
| Name | Profile |
|------|---------|
| Acuity Scheduling | https://optimly.ai/brand/acuity-scheduling |
| Calendly | https://optimly.ai/brand/calendly |
| Easyappointments | https://optimly.ai/brand/easyappointments |
### AI-Suggested Alternatives
- Calendly (https://optimly.ai/brand/calendly)
### Buyer Intent Signals
#### 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.
### Links
- Canonical page: https://optimly.ai/brand/calendso-legacy-split
- JSON endpoint: /brand/calendso-legacy-split.json
- LLMs.txt: /brand/calendso-legacy-split/llms.txt