Open-source licenses define how software can be used, modified, and shared. Choosing the right one depends on your project’s goals, legal considerations, and flexibility needs. Below is a breakdown of some of the most widely used licenses.
✅ Allows: Free use, modification, and distribution.
⚖️ Requirements: Give credit to the original author and comply with the included patent grant.
❌ Restrictions: Cannot use the original author’s trademarks.
🔹 Best For: Open-source projects needing strong legal protection, including businesses.
🔖 Used By: Android, Apache HTTP Server
✅ Allows: Free use, modification, and distribution.
⚖️ Requirements: Any modifications must remain open-source (copyleft requirement).
❌ Restrictions: Cannot be combined with closed-source/proprietary software.
🔹 Best For: Projects that should always remain open-source.
🔖 Used By: Linux Kernel, WordPress
✅ Allows: Maximum freedom—modify, distribute, and use as needed.
⚖️ Requirements: Must retain the original copyright notice.
❌ Restrictions: The author is not liable for any issues.
🔹 Best For: Simple, permissive licensing for all kinds of projects.
🔖 Used By: React, jQuery, Ruby on Rails
✅ Allows: Free use, modification, and distribution.
⚖️ Requirements: Must retain the copyright notice and disclaimer.
❌ Restrictions: No liability for the author.
🔹 Best For: Minimal restrictions, simple open-source compliance.
🔖 Used By: NetBSD, FreeBSD
✅ Allows: Same as BSD 2-Clause with an additional requirement.
⚠️ Requirements: Must retain copyright notice and avoid unauthorized name usage.
❌ Restrictions: Cannot use the project’s name for promotion without permission.
🔹 Best For: Protecting an open-source project’s reputation while keeping it flexible.
🔖 Used By: PostgreSQL, Apple OS X
✅ Allows: Free modification, use, and distribution.
⚖️ Requirements: Must retain the copyright notice.
❌ Restrictions: No liability or warranty protection.
🔹 Best For: C++ libraries and projects needing permissive licensing.
🔖 Used By: Boost C++ Libraries
✅ Allows: Complete public domain use with no restrictions.
⚖️ Requirements: None—attribution is optional.
❌ Restrictions: No liability protection.
🔹 Best For: Creative works, images, text, and datasets intended for unrestricted use.
🔖 Used By: Unsplash, Pixabay
✅ Allows: Free modification, use, and distribution.
⚖️ Requirements: Modifications must remain open-source, but proprietary components can be combined.
❌ Restrictions: No liability protection.
🔹 Best For: Enterprise software that balances open-source and proprietary needs.
🔖 Used By: Eclipse IDE
✅ Allows: Same as GPL v3.0 with an additional requirement.
⚠️ Requirements: If software is used over a network (e.g., web apps), the source code must be made available to users.
🔹 Best For: Open-source web applications that must remain free.
🔖 Used By: Nextcloud, Mastodon
✅ Allows: Free use, modification, and distribution.
⚖️ Requirements: Modified parts must be open-source, but linking to proprietary software is allowed.
🔹 Best For: Libraries that can work with both open-source and proprietary software.
🔖 Used By: FFmpeg, Qt
✅ Allows: Free use, modification, and distribution.
⚖️ Requirements: Only modified files need to be open-source.
🔹 Best For: Software that balances open-source with proprietary components.
🔖 Used By: Firefox, Thunderbird
✅ Allows: Complete public domain release.
⚖️ Requirements: None—no restrictions at all.
🔹 Best For: Projects where the author wants full public freedom.
| License | Freedom Level | Open-Source Requirement | Best For | Used By |
|---|---|---|---|---|
| Apache 2.0 | High | No | Businesses, patent protection | Android, Apache HTTP Server |
| GPL v3.0 | Medium | Yes | Always-open-source projects | Linux Kernel, WordPress |
| MIT | Maximum | No | All kinds of projects | React, jQuery, Ruby on Rails |
| BSD 2-Clause | High | No | Simple open-source compliance | NetBSD, FreeBSD |
| BSD 3-Clause | High | No | Protecting project reputation | PostgreSQL, Apple OS X |
| Boost 1.0 | High | No | C++ libraries | Boost C++ Libraries |
| CC0 | Complete | No | Public domain content | Unsplash, Pixabay |
| EPL 2.0 | Medium | Yes (for modifications) | Enterprise software | Eclipse IDE |
| AGPL v3.0 | Medium | Yes (even for network use) | Open-source web apps | Nextcloud, Mastodon |
| LGPL v2.1 | Medium | Yes (for modified parts) | Open/proprietary software mix | FFmpeg, Qt |
| MPL 2.0 | Medium | Yes (only modified files) | Mixed-source projects | Firefox, Thunderbird |
| Unlicense | Maximum | No | Full public domain release | - |
Choosing the right license is crucial—consider openness (GPL), flexibility (MIT), or legal protection (Apache 2.0). Hope this helps in making an informed decision! 🚀