Open-Source Workflow/Automation Tools

Ranked by Popularity

1. n8n — Very Popular
   • Widely used for general workflow automation with a visual builder.
   • Large community and many integrations.
   • Often ranked #1 in workflow tool lists.
2. Node-RED — Highly Popular
   • Strong open-source user base, especially for IoT and integration workflows.
   • Long history and strong community.
3. Apache Airflow — Very Popular (in data/engineering)
   • Dominant in data engineering and complex scheduled pipelines; huge adoption in enterprise data teams.
4. Activepieces — Fast-Growing
   • Newer but rapidly rising in many “top open-source automation” lists.
   • Growing ecosystem and community interest.
5. Huginn — Popular Niche Tool
   • Known in self-hosted automation communities for event-based agents.
6. Windmill — Emerging
   • Increasingly included in open-source automation tool lists; still smaller compared to older players.
7. Kestra — Growing
   • Gaining attention for scalable orchestration, less mainstream than Airflow but rising.

Ranked with Brief Comments

Rank	Tool	Why it’s popular
1	n8n	General workflow automation; strong community; visual UI.
2	Node-RED	Mature, widely used in IoT and integrations; broad ecosystem.
3	Apache Airflow	Very popular in data engineering and ETL use cases.
4	Activepieces	Newer but rapidly adopted; mentioned in many 2025 tool lists.
5	Huginn	Known in privacy-focused and scriptable automation circles.
6	Windmill	Emerging workflow tool, gaining traction.
7	Kestra	Growing in developer orchestration space.