What are some differences between MPLv2 and EPLv2?

Question

I understand that both are similar in terms of copyleft (at file-level), compatibility with GPL family of licenses (only the first derivative of the files would need to be dual-licensed under the terms of both GPL and [E/M]PL), patent grants, and trademark use.

The only difference I know is MPLv2 code is also implicitly licensed under any future versions of the MPL license (and these future versions of the MPL can only be released under the stewardship of the Mozilla Foundation), whereas EPLv2 has no such requirement.

What are some other differences which need to be considered when choosing MPLv2 and EPLv2?

Answer 1

The EPL is not compatible with the GPL. The MPL is compatible with the GPL.

For that reason I would recommend the MPL if you could choose between the EPL or MPL.

Answer 2

Reading through both licenses, I found several minor differences.

• As stated by techboyg5, the Mozilla Public License Version 2.0 is compatible with the GPL by default unless provided with the notice described in MPL Exhibit B (see MPL section 1.4), while the Eclipse Public License - v 2.0 is by default incompatible with the GPL unless provided with the notice described in EPL Exhibit A (see EPL section 3.2).
• The patent retaliation clause of the two licenses differs in the rights it revokes from the user who initiates litigation against a contributor to the licensed software for patent infringement claims. Under the EPL, only the rights to other patent claims otherwise infringed by use of the software are revoked from the user instituting patent litigation (see EPL section 7, paragraph 2), while under the MPL, all rights, both to intellectual property and patent claims, are revoked upon initiating patent litigation (see MPL section 5.2). The MPL excludes counter-claims and cross-claims from patent retaliation, while the EPL includes both. The MPL therefore provides a stronger deterrent against suing for patent infringement.
• The MPL recommends the notice in MPL Exhibit A to be provided on each file of source code (see MPL section 1.4), while the EPL requires the full license to be distributed with the program (see the EPL license header). Legally, this does not make a difference, but practically, source code borrowed from a program is more likely to retain a clear reference to its license under the MPL rather than the EPL as the license information is stored within each file. As both licenses are applicable to the source code at file-level scope, the MPL makes reuse of covered code easier. (Note that the MPL also allows use of a single license file if including the license in each file is not possible or undesirable; see MPL Exhibit A.)

The only difference I know is MPLv2 code is also implicitly licensed under any future versions of the MPL license (and these future versions of the MPL can only be released under the stewardship of the Mozilla Foundation), whereas EPLv2 has no such requirement.

Both the MPL v2.0 and EPL v2.0 allow contributors to optionally release code either under the license by which it was originally released or under future published versions of the respective licenses. As far as I can tell, neither license implicitly upgrades to a future version. See MPL section 10.2 and EPL section 7, paragraph 4.