Mozilla Public License 2.0

Mozilla Public License Version 2.0

File-Level Copyleft

MPL-2.0 is a weak copyleft license. Modified files must remain under MPL-2.0, but you can combine MPL-2.0 code with proprietary or differently licensed code in the same project, provided the MPL-2.0 files stay available. This is weaker than GPL (which covers the entire derivative work) but stronger than MIT/Apache (which have no copyleft).

The full text of the Mozilla Public License 2.0 is available at https://www.mozilla.org/en-US/MPL/2.0/.

What this means

The MPL-2.0 is a file-level copyleft license created by Mozilla. Key provisions:

• Use, modify, distribute: You can use, modify, and distribute MPL-2.0 code freely.
• File-level copyleft: If you modify an MPL-2.0 file, the modified file must remain under MPL-2.0 and its source must be made available.
• Larger works: You can combine MPL-2.0 files with files under other licenses (including proprietary) in a larger work. Only the MPL-2.0 files themselves carry the copyleft obligation.
• Patent grant: Contributors grant a patent license for their contributions.
• GPL compatibility: MPL-2.0 code can be relicensed under GPL-2.0+, LGPL-2.1+, or AGPL-3.0+ if needed for compatibility.

Where this applies

Some Rust crates in the ecosystem use MPL-2.0 (e.g., certain crypto libraries, configuration parsers). When the KBVE monorepo depends on an MPL-2.0 library, the source of any modified MPL-2.0 files is made available as required. Unmodified MPL-2.0 dependencies used as-is satisfy the license by pointing to the upstream source repository.