CPAL (Common Public Attribution License)
An MPL-derived licence that requires the original author's name or logo to appear in the user interface – the textbook case of badgeware.
Socialtext wrote it and got it OSI-approved in 2007. Underneath is MPL 1.1, with its file-level weak copyleft, plus two additions: an exhibit in which the licensor specifies the attribution every user must see, and a clause that treats network use as distribution. Run the code as a web service and you owe the same obligations as if you had shipped it.
In the late 2000s badgeware was how commercial open source companies kept their brand stamped on every fork. Critics pointed out that a mandatory logo on every screen is closer to advertising than to freedom. The FSF considers the licence free but GPL-incompatible, and it is rarely chosen today.