Software Licences Explained #
Licenses are responses to historical pressures, not abstract ideologies. 👉 It’s basically choosing a social contract, not a legal detail.
TLDR #
- MIT → Freedom without obligations
- Apache 2.0 → Freedom with legal safety
- GPL → Freedom with reciprocity
Licence summary #
| License | Birthdate | Creator / Origin | Mental model | Commercial use? | Closed-source allowed? | What must be shared | Famous examples | Who profits |
|---|---|---|---|---|---|---|---|---|
| Unlicense | ~2010 | Public domain attempt | Do literally anything. | ✅ Yes | ✅ Yes | Nothing | — | Anyone |
| MIT | 1988 | MIT (academia) | Take it and run. | ✅ Yes | ✅ Yes | Keep license notice | NumPy, Flask, Requests | Everyone |
| BSD (2/3-Clause) | 1988 | UC Berkeley | Open code, no strings. | ✅ Yes | ✅ Yes | Keep copyright notice | FreeBSD, OpenSSH | Apple, Juniper |
| Apache 2.0 | 2004 | Apache Software Foundation | Open, but legally safe. | ✅ Yes | ✅ Yes | Preserve notices + patent peace | Kubernetes, Spark, Kafka | Google, Confluent |
| MPL 2.0 | 1998 | Netscape / Mozilla | Open files, closed products. | ✅ Yes | ⚠️ Except MPL files | Modified MPL files | Firefox | Mozilla |
| LGPL | 1991 | Free Software Foundation | Share the core, not the app. | ✅ Yes | ⚠️ App yes, library no | Changes to LGPL library | glibc, FFmpeg | Red Hat, IBM |
| GPL (v2/v3) | 1989 (v1) | Richard Stallman (FSF) | Take it, but give back. | ✅ Yes | ❌ No (if distributed) | Full source + same license | Linux kernel, WordPress, Git | Automattic, Red Hat, Canonical, GitLab |
| AGPL | 2007 | FSF + Affero Inc. | SaaS must share too. | ✅ Yes | ❌ No (incl. SaaS) | Source, incl. network use | Nextcloud, Mastodon | Nextcloud GmbH |
| Proprietary | — | Vendor-defined | You rent, not share. | ⚠️ Limited | ✅ Yes | Fees, data, compliance | Windows, macOS | Microsoft, Apple |
How do companies monetize open source? #
Most organizations and individuals make money with open-source software through:
- Hosting, support, subscriptions, enterprise services, and trademarks (GPL, AGPL, LGPL)
- Cloud services and managed platforms (Apache 2.0, BSD, MIT)
- Support, dual licensing, enterprise contracts (LGPL)
- Products, hardware, internal use (BSD)
- Licenses, subscriptions, lock-in (Proprietary)
The monetization model is often similar across licenses, focusing on added value, services, or proprietary extensions rather than direct software sales.
How to choose a license? #
Ask yourself one simple question first:
❓ Am I okay with someone taking my code, improving it, and never contributing back?
-
Yes → choose MIT
Maximum adoption, zero friction. Your code can go anywhere. -
Yes, but I want legal & patent safety → choose Apache 2.0
Same freedom as MIT, with stronger protections for companies. -
No → choose GPL
You allow commercial use, but improvements must stay open.
There is no “best” license — only a license that matches your values and goals.
License philosophy and intent #
| License | Philosophy | Intent |
|---|---|---|
| GPL (v2/v3) | Strong copyleft / reciprocity | Ensure that all distributed modifications remain open-source under the same license, protecting user freedoms and preventing private capture of community code. |
| Apache 2.0 | Permissive with legal safety | Promote broad collaboration and commercial adoption while providing explicit patent protections and requiring preservation of notices. |
| MIT | Ultra-permissive | Maximize reuse and adoption by imposing minimal restrictions, allowing selling, re-licensing, and closed-source derivatives. |
| LGPL | Weak copyleft (library-focused) | Allow proprietary applications to link against open libraries while ensuring improvements to the library itself remain open. |
| AGPL | Network copyleft | Close the SaaS loophole by requiring source code disclosure to users who interact with the software over a network. |
| BSD (2/3-Clause) | Permissive and business-friendly | Enable nearly unrestricted use, including proprietary and commercial use, as long as copyright notices are retained. |
| MPL 2.0 | File-level copyleft | Require sharing of modified MPL-licensed files while allowing combination with proprietary code in larger systems. |
| Unlicense / Public Domain | No philosophy enforced | Remove all restrictions entirely, placing the code effectively in the public domain for unrestricted reuse. |