Software License Comparison
Compare open source software licenses. MIT, Apache, GPL, BSD, LGPL. Understand permissions, conditions, limitations. Choose right license for your project.
License Types
Permissive: Minimal restrictions
Copyleft: Derivatives must share
Proprietary: Closed source
License Comparison Table
| License | Type | Modify | Distribute | Commercial | Patent |
|---|---|---|---|---|---|
| MIT | Permissive | ✓ | ✓ | ✓ | ✗ |
| Apache 2.0 | Permissive | ✓ | ✓ | ✓ | ✓ |
| GPL v3 | Copyleft | ✓ | ✓ | ✓ | ✓ |
| LGPL | Weak Copyleft | ✓ | ✓ | ✓ | ✗ |
| BSD 3-Clause | Permissive | ✓ | ✓ | ✓ | ✗ |
| ISC | Permissive | ✓ | ✓ | ✓ | ✗ |
| MPL 2.0 | Weak Copyleft | ✓ | ✓ | ✓ | ✓ |
| Proprietary | Closed | ✗ | ✗ | ✓ | ✗ |
Popular Licenses Explained
MIT (Permissive): Most permissive, minimal restrictions
Best for: Libraries, open source projects
Apache 2.0 (Permissive): Permissive with patent protection
Best for: Enterprise, corporate projects
GPL v3 (Copyleft): Strong copyleft, derivatives must be GPL
Best for: Open source projects wanting freedom
LGPL (Weak Copyleft): Linking allowed without derivative license
Best for: Libraries that can be used commercially
BSD 3-Clause (Permissive): Permissive, no endorsement clause
Best for: Academic, research projects
ISC (Permissive): Simplified MIT-like license
Best for: npm packages, Node.js projects
Choosing a License
Want maximum freedom? Use MIT or ISC. Want patent protection? Use Apache 2.0. Want derivatives open? Use GPL v3. Library that others can link? Use LGPL. Academic project? Use BSD. Commercial product? Proprietary. Consider: community, enterprise use, legal needs, contribution expectations.
License Requirements
Include License: Copy in distribution
State Changes: Note modifications
Same License: Derivatives same license
Attribution: Credit original author
Important Notes
Consult legal counsel for commercial decisions. This is informational only. License compatibility matters for combined projects. GPL derivatives must remain GPL. Apache/BSD/MIT code can be made proprietary. Check dependencies' licenses. Many projects use multiple licenses.