GNU Affero General Public License v3.0
Like GPL, but the copyleft extends to network use. If you run it as a service, you must share your source.
Commercial use
✓ Yes
Modify
✓ Yes
Distribute
✓ Yes
Must open source changes
✓ Yes
Must attribute
✓ Yes
Patent grant
✓ Yes
What this license means
The AGPL closes the 'SaaS loophole' in the GPL. If you modify AGPL software and let users interact with it over a network (like a web app), you must make your modified source code available. This is the strongest copyleft license — it ensures that even hosted versions of the software remain open.
When you encounter this license
Be cautious. If you're using an AGPL library as part of your SaaS product, you may need to open-source your entire application. Many companies have blanket policies against AGPL dependencies. Check with your legal team before adopting.
Watch out for
This is the license companies fear most. MongoDB, Grafana, and others have moved to custom licenses (SSPL, BSL) because AGPL was too permissive for their business model while still scaring away enterprise users. If you see AGPL, assume you cannot use it in a proprietary SaaS without legal review.
Tools using GNU Affero General Public License v3.0 (29)
The open LMS by Instructure, Inc.
Zammad is a web based open source helpdesk/customer support system.
Open source email platform
Open source APM with OpenTelemetry traces, metrics, and logs
Aesthetic, minimalist platform for learning Japanese inspired by Duolingo and Monkeytype, built with Next.js and sponsored by Vercel. Beginner-friendly with plenty of good first issues - all contributions are welcome!
Offline multi-agent simulation & prediction engine. English fork of MiroFish with Neo4j + Ollama local stack.
🐋 Ansible playbook which helps you host various FOSS services as Docker containers on your own server
Expose Docker containers as Tailscale Services using label-based configuration.
High-performance analytical database combining DuckDB SQL engine, Parquet storage, and Arrow format. 18M+ records/sec.
This guide is for informational purposes only and does not constitute legal advice. For licensing decisions in commercial products, consult a qualified attorney.