Skip to main content

MPL 2.0

Table of Content

  • Introduction
  • Requirements
  • About Mozilla Public License 2.0 Licensed Code
  • Other Weak Copyleft Licenses vs. MPL 2.0
  • Mozilla Public License 2.0 Use Cases
  • The Mozilla Public License 2.0's Future

Introduction

The Mozilla Foundation is most often associated with its browser, Mozilla Firefox. Mozilla is also known among open source software contributors for their dedication to maintaining the internet a free and public resource, a purpose that aligns with the spirit of OSS development.the Mozilla Foundation developed its own open source licence, the Mozilla Public License.

The Mozilla Public License (MPL) was first issued in 1998, with a significantly revised version 1.1 following the next year. Mozilla Public License 2.0 debuted more than a decade later, in 2010, and has remained the MPL of choice ever since.

The MPL 2.0 is neither a permissive license like the MIT License (which allows for extremely limited usage of licensed work) nor a strong copyleft license like the GPL v2. MPL 2.0 falls in the middle of these two. Permissive and copyleft licenses are the two types of open source software licenses. There are two types of copyleft licenses strong and weak. MPL 2.0 is a weak copyleft license.

Requirements

The distinction between the two types of copyleft licenses is the scope of shared source code. Strong copyleft licenses, such as the GPL v2 and GPL v3, enable users to modify and redistribute the original code, but only if they make the whole programme accessible under the same license. To put it another way, the modified code must be licensed under the original copyleft license, which requires source code disclosure.

Weak copyleft licenses, such as the Mozilla Public License 2.0, also require users to reveal their source code changes, but only for a limited range of code. If an author modifies any of the original files, they must provide the updated files with the code and licence them under the MPL.

The author can mix MPL'd code with closed-source code to produce an aggregate work if they maintain the MPL'd code in separate folders. The new code files can either remain confidential or be distributed under a different license. File-based copyleft is a term used to describe this type of copyleft.

Users must additionally include the original copyright notice in addition to the requirement that developers disclose modifications to the original project's source code. MPL 2.0 requires users to declare that the code is licensed under the MPL and to tell where they may obtain the license. It is not essential to provide the entire license wording.

About Mozilla Public License 2.0 Licensed Code

Users of MPL 2.0-licensed code may do the following:

Commercial applications can benefit from the code. MPL'd code can be incorporated in commercially marketed software. Make a code change. Authors have the ability to change or modify the licensed code. Distribute the code to as many people as possible. A person or a corporation can make their modified versions of the code available to the public. Make use of patent claims. Patent rights are explicitly granted to users by contributors to the licenced code.Put a warranty in place. The licensing conditions allow users of the open source code to bind the licensed programme to a guarantee. Binaries with a sublicense. In the context of an aggregate work, a developer may place binaries under a separate license.

This license does not provide trademark rights, which means that users of MPL 2.0-licensed code cannot use the original project's or contributors' trademarks, names, logos, or other identifiers. The license further says that it does not give a guarantee and that contributors will not be held accountable for any legal difficulties that may emerge as a result of software that incorporates the code.

Other Weak Copyleft Licenses vs. MPL 2.0

  • MPL 2.0 Vs. GNU Lesser Public License (LGPL)

    The LGPL License is the only GPL license with a weak copyleft clause. In general, this license covers libraries, whereas the MPL 2.0 covers binaries. It was dubbed the "Library" General Public License at first. Any bigger work that alters or statically links to the library must be released under the LGPL, and any code modifications must be listed and disclosed. An programme that just uses the library, on the other hand, does not need to be licensed under the LGPL, and the source code does not need to be made public.

    Users are not permitted to license the code under the LGPL. Anyone who incorporates the code into a consumer device must also supply any installation information required to update and reinstall the programme.This is not the case with MPL.

  • MPL 2.0 Vs. Eclipse Public License 2.0 (EPL)

    The Eclipse Foundation released the most recent version of the EPL in August of 2017. Both of these licenses are similar in that they apply to files rather than libraries and allow for the sublicensing of aggregate works. The EPL differs in that it provides contributors with additional legal safeguards. Any firm that utilises EPL’d code in commercial software must defend the code’s contributors should any lawsuits or damages arise regarding that software. Patent rights are explicitly granted in both licenses.

Mozilla Public License 2.0 Use Cases

Weak copyleft licenses like the Mozilla Public License 2.0 fill a niche between strong copyleft licenses, such as the GPLs, and permissive ones like MIT or Apache License 2.0. As a result, it serves specific use cases for both authors and companies that rely on open source software.

  • Authors

    The Mozilla Public License 2.0 is a weak copyleft license that allows OSS writers to safeguard their contributions to a piece of OSS while still allowing their work to be integrated into well-known and successful private products. For developers looking to strike a compromise between these two objectives, the license may provide the best of both worlds MPL 2.0 is especially useful for programmes that support proprietary plug-ins.

    The Mozilla Public License 2.0 includes an express patent license as well as other phrases that explain the license's scope. It includes an implicit license disclaimer as well as a strong defence termination provision. Unlike the Apache License 2.0, which simply terminates patent rights, Mozilla 2.0 provides a powerful deterrent against patent claims by terminating the copyright license as well.

  • Users

    The Mozilla Public License 2.0 offers a variety of advantages to licensed code users.

    The express transfer of patent rights, for example, shields users against some patent litigation brought by contributors. The possibility to mix MPL'd code with proprietary works is another advantage. The license encourages businesses to participate in and contribute back to the open-source community while maintaining the competitive benefits of closed-source software.

The Mozilla Public License 2.0's Future

According to a recent analysis of GitHub projects, the Mozilla Public License 2.0 was utilised by about 1.4 percent of those on the platform. It was the only copyleft license that appeared in a large number of projects.

When you combine this with the fact that MPL 2.0 is positioned as a bridge between GPL-like and permissive licenses, it's apparent that MPL 2.0 offers a unique choice for open-source projects.