Why is the project no longer MIT-licensed? Why the downgrade from almost-public-domain to copy{lefted & righted}?

[xplshn]

[synesthesiam]

This version of Piper embeds espeak-ng directly to simplify deployment instead of having a separate piper-phonemize library. Based on my understanding of espeak-ng's license (GPLv3), this now makes Piper GPLv3.

[xplshn]

This version of Piper embeds espeak-ng directly to simplify deployment instead of having a separate piper-phonemize library. Based on my understanding of espeak-ng's license (GPLv3), this now makes Piper GPLv3.

Ah, makes sense. However, it’s a common misconception that simply including or vendoring a GPLv3 library forces the rest of the project to switch licenses. That only applies when your own code is a derivative work of the GPL code.

In this case, you can keep your code MIT-licensed, and just acknowledge in the LICENSE file (or a NOTICE section) that the project includes or vendors espeak-ng, which remains under GPLv3. That way, Piper itself stays MIT, but the bundled dependency is clearly marked as GPLv3.

I hope coming back to the original licensing terms can be considered

[memchr]

That only applies when your own code is a derivative work of the GPL code.

It's not clear-cut. The FSF's stance is that an executable which links to a GPL library is considered a derivative work¹². However, as far as I know, this has never been tested in court. So perhaps you could interpret it this way³.

Footnotes

1. https://www.gnu.org/licenses/gpl-faq.html#IfLibraryIsGPL ↩

2. https://www.gnu.org/licenses/gpl-faq.html#GPLStaticVsDynamic ↩

3. https://www.linuxjournal.com/article/6366 ↩

[xplshn]

That only applies when your own code is a derivative work of the GPL code.

It's not clear-cut. The FSF's stance is that an executable which links to a GPL library is considered a derivative work12. However, as far as I know, this has never been tested in court. So perhaps you could interpret it this way3.

Footnotes

1. https://www.gnu.org/licenses/gpl-faq.html#IfLibraryIsGPL ↩
2. https://www.gnu.org/licenses/gpl-faq.html#GPLStaticVsDynamic ↩
3. https://www.linuxjournal.com/article/6366 ↩

It has no precedents in a court of law as of 2025 in the U.S. I've been looking for a while and found nothing. It seems like a wild assertion by the FSF and nothing more than that.

But once again, this project is open source. It would not be affected in any case because binaries are not provided, and even if they were, the package itself (and its recipe) could be marked GPLv3.

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I honestly hate how tyrannical and absurd the FSF is. Superior and more efficient software should make it into products, even if the developers do not get attribution, the enhancements and innovations reach everyone that way.

I'd much prefer my router to run Linux + Busybox rather than Huawei's proprietary thing, but once again. The GPL prohibits "fair" competition by enforcing companies give up anything that they have in their advantage against competitors.

Companies only use the GPL to protect themselves, just like Mozilla does with the MPL, and how Brave does with it as well, or Apple with the Apple License v2, which is a copylefted license, or ID Tech, they are big fans of the GPL... Same for Valve and a lot of others...

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Just my $2 cents, would love to see piper be MIT-licensed again

[Joseffb]

I agree. It makes it hard to simply uses as a standalone component. The GPLv3 went to crazy land. GPLv2 is much better IMO and MIT better still.

[synesthesiam]

I'm not a lawyer and I can't afford a lawsuit, so I'm taking a more conservative view of the GPL here 😄
I am working on my own phonemizer that will be part of an Apache 2 version of Piper in the future.

For now, I've told people that if they get approval from the espeak-ng project, they're welcome to treat the Piper code as Apache 2.