Yahoo! Public License is a

free software license A free-software license is a notice that grants the recipient of a piece of software extensive rights to modify and redistribute that software. These actions are usually prohibited by copyright law, but the rights-holder (usually the author) ...

Yahoo! Yahoo (, styled yahoo''!'' in its logo) is an American web portal that provides the search engine Yahoo Search and related services including My Yahoo, Yahoo Mail, Yahoo News, Yahoo Finance, Yahoo Sports, y!entertainment, yahoo!life, and its a ...

. It is used among others by old versions of the collaborative software

Zimbra Zimbra Collaboration, formerly known as the Zimbra Collaboration Suite (ZCS) before 2019, is a collaborative software suite that includes an email server and a web client. Zimbra was initially developed by LiquidSys, which changed their name ...

. It is approved by the

Free Software Foundation The Free Software Foundation (FSF) is a 501(c)(3) non-profit organization founded by Richard Stallman on October 4, 1985. The organisation supports the free software movement, with the organization's preference for software being distributed ...

as a free (however GPL- incompatible) software license.

References

Free and open-source software licenses Copyleft software licenses {{free-software-stub de:Zimbra#Editionen