[6] Notable projects that use the Unlicense include youtube-dl,[7] Second Reality,[8] and the source code of the 1995 video game Gloom.

[9] In a post published on January 1 (Public Domain Day), 2010, Arto Bendiken, the author of the Unlicense, outlined his reasons for preferring public domain software, namely: the nuisance of dealing with licensing terms (for instance license incompatibility), the threat inherent in copyright law, and the impracticability of copyright law.

In this post, he explained that the Unlicense is based on the copyright waiver of SQLite with the no-warranty statement from the MIT License.

[12] In December 2010, Mike Linksvayer, the vice president of Creative Commons at the time, wrote in an identi.ca conversation "I like the movement" in speaking of the Unlicense effort, considering it compatible with the goals of the CC Zero (CC0) license, released in 2009.

[3] However, in July 2022, the CC0 license became unsupported and software to be released in the Fedora distribution must not be under CC0, due to CC0 not waiving patent rights.