Open-source developers will have their licensing issues simplified, with Mozilla releasing an update to its public licence to remove complexities and increase compatibility with other open-source licences.
Changes to the MPL have resulted in a shorter, simpler licence.
(Screenshot by Michael Lee/ZDNet Australia)
The Mozilla Public Licence (MPL) is a "file-level copyleft" licence designed to encourage contributors to share modifications they make to MPL-licensed code, while still allowing users to create projects that combine MPL-licensed code with code under other open or proprietary licences.
The changes have resulted in the simplification and shortening of the licence by removing unnecessary elements and provides greater patent protection for contributors, which is necessary to copyright changes over the last decade.
Although the MPL was designed to sit between the Apache licence, which doesn't require modifications to open-source code to be shared upon distribution, and the GNU General Public Licence (GPL), which requires modifications to be shared under a broader set of circumstances than MPL, the Free Software Foundation previously found 1.1 to be incompatible with GPL.
This would mean if a developer were to combine MPL- and GPL-licensed codes, they could be open to legal action if they attempted to distribute the resultant code since it would be impossible to meet conflicting licensing obligations.
The result has been that Mozilla and others licensing their code under MPL have had to re-licence their work several times to make the code available in a form that would not open subsequent contributors to litigation. The problem with this approach has been that developers who make changes to licensed code can not necessarily re-licence their contributions under multiple licences. These contributions are then only available under a specific licence, forcing developers to adopt a particular licensing arrangement if they wish to use contributed code.
The MPL 2.0 public licence has since been approved by the Free Software Foundation as compatible, as it provides developers with an option to create a "larger work" that satisfies the requirements of GPL and MPL by requiring code to be additionally licensed under both GPL and MPL. This means that future contributors would have the ability to pick which licence they wish to use, but have identical code no matter which one was picked.