open-source-licensing
Open-Source Licensing
Disclaimer: This skill provides general educational information about legal topics relevant to software development. It is not legal advice. Laws vary by jurisdiction and change frequently. Always consult a qualified attorney licensed in the relevant jurisdiction before making legal decisions for your organization.
Overview
Open-source software is the foundation of modern development, but every OSS component carries license obligations that can affect how you distribute your software. A single incompatible dependency can force you to relicense your product, release proprietary source code, or remove the component entirely. Understanding the spectrum of open-source licenses -- from permissive to strong copyleft -- is essential for any team that builds on open-source foundations.
License Categories
| Category | Obligations | Examples |
|---|---|---|
| Permissive | Minimal: attribution, include license text, no warranty disclaimer | MIT, Apache 2.0, BSD 2-Clause, BSD 3-Clause, ISC |
| Weak Copyleft | Modifications to the library must be shared under the same license, but you can link from proprietary code | LGPL 2.1, LGPL 3.0, MPL 2.0, EPL 2.0 |
| Strong Copyleft | Derivative works must use the same license -- this is the "viral" effect | GPL 2.0, GPL 3.0, AGPL 3.0 |
| Network Copyleft | Copyleft is triggered even by network use (providing the software as a service) without traditional distribution | AGPL 3.0 |