Happy Public Domain Day 2025!

by Valentino Giudice on

This blog post is dedicated to the public domain through CC0.

I am not a lawyer and this is not legal advice.

The 1st of January is Public Domain Day: the day in which a new batch of works enters the public domain and becomes free for all to build upon, promoting progress, culture and creativity.

My first blog post on Public Domain Day was in 2024. This is my second one. There isn’t much to celebrate with regard to this blog, as I have only published one post between these two. I am working locally, although very slowly, on other articles and I hope to publish more this year. In the meanwhile, I celebrate the public domain again through this post.

The duration of copyright protection varies across jurisdiction, and so does what works enter the public domain today. The Public Domain Review features works in the public domain, most of which worldwide, but not all, according to the relevant labels.

This year the original Popeye character enters the public domain in the United States, where it’s treated as a work for hire, thus with a different copyright protection, while in Italy, which makes no such distinction, it has been unprotected since 2009, 70 years after the death of the author. Conversely, in Italy, which doesn’t apply the rule of the shorter term to US works, the original Mickey Mouse, which was the most remarkable new entry to the public domain in the US last year, remains protected.

Public domain software

Computer programs, whether in source or object code, are protected as literary works. In principle, like all other works, they are meant to enter the public domain automatically after the copyright term, but, due to the recent and evolving nature of software, there is no useful pool of programs that have.

Several computer programs and software libraries have been willingly dedicated to the public domain. This can happen through a waiver, such as the Unlicense, or through public-domain-equivalent licences, such as the WTFPL, the Zero-Clause BSD licence or MIT No Attribution License. When the source code of a public domain program is available, it also qualifies as free and open source software.

Below are some examples of public domain software:

Overall, despite its importance and validity, the public domain remains a relatively uncommon choice by software developers and most free and open source software is not in the public domain.

Public domain datasets

Databases (or “compilations”) are covered by copyright, if the selection or arrangement of their contents constitute the author’s own intellectual creation, and, in the European Union and the United Kingdom, by sui generis rights, according to a sweat of the brow doctrine, for a substantial investment in obtaining, verifying or presenting their contents. These database rights exist without prejudice to those subsisting in the works incorporated into a database.

Large amounts of high-quality data can make a great difference in the fields of machine learning and data mining. The practice of training models on data collected through web scraping has sparked debate and raised legal questions which are yet to be answered.

The availability of public domain datasets of public domain material can reduce legal uncertainty regarding the use of data, of trained models and of their outputs.

Databases can be dedicated to the public domain through CC0, the Open Data Commons Public Domain Dedication and License or other similar legal tools.

Below I describe some datasets of interest:

A fundamental axiom of copyright is that it cannot protect facts and databases are, commonly, largely factual. The boundary between protectable and unprotectable elements of a database can be hard to determine and relevant legal questions regarding the use of data remain unanswered. In addition, data is often compiled from multiple sources, increasing the complexity of providing attribution in the specific fashion required by licences and potentially leading to recursive attribution stacking.

The public domain is a good option for maximizing the reusability of data, especially when intended for scientific purposes. CASIMIR Rome Meeting participants recommended that materials and data be shared under the least restrictive terms possible and advocated for strongly resisting any restrictions on use, suggesting the use of CC0.

CC0 is the default licensing options for data for some research repositories, such as Figshare and multiple Dataverse instances. Dryad requires that all published data be in the public domain.

Assets for software

Often, computer programs need to include, or to be combined with, elements which are not strictly software, such as art. Producing these can be time consuming and requires abilities a software developer might not have. The availability of public domain assets can be valuable.

Kenney releases its game assets under CC0. OpenGameArt platform provides game art under free and open licences, much of which in the public domain.

The legal landscape of typefaces is complex and varies by jurisdiction. A large collection has been dedicated to the public domain through CC0 by Typodermic Fonts, a digital type foundry. Many more public domain typefaces can be found online, such as Tuffy, Programma and pixel fonts by Not Jam.

Italy’s classical masterpieces

As I remarked last year, in Italy, some articles in the Cultural Heritage Code hinder the commercial uses of works which are parts of its rich cultural heritage.

The Cultural Heritage Code has lead to decisions against uses of David by Michelangelo, which have attracted criticism. It’s also not the only work being restricted for this reason.

Additional resources