LicensesMPL-2.0
Weak CopyleftOSI Approved
Mozilla Public License 2.0
A file-level copyleft license: modified MPL-covered files stay open, but larger combined works can remain proprietary.
A pragmatic middle ground between permissive licenses and strong copyleft.
Family
Weak Copyleft
Reciprocity
File-level
Patent Grant
Included
Closed Source
Allowed
What It Lets You Do
- Commercial and private use.
- Distribution inside larger proprietary products if MPL-covered files stay compliant.
- Modification and redistribution.
What It Requires
- Modified MPL-covered files must remain under MPL when distributed.
- Source for covered files must be made available.
- Preserve notices and required license text.
Advantages
- Encourages contributions to the core without scaring off commercial adopters.
- Usually easier to approve than GPL-style licenses.
- Includes a patent grant.
Tradeoffs
- Less frictionless than MIT or Apache.
- Requires teams to track which files are MPL-covered.
Restrictions And Gotchas
- Reciprocity is triggered at the file level, so packaging discipline matters.
- No trademark rights are granted.