## What is the public domain?
The public domain is a wealth of cultural works, information and knowledge that can be accessed, shared and reused any without restrictions.
## How do I know whether or not a work is in the public domain?
Determining whether or not a given work is in the public domain is not always straightforward. Many countries have different rules, which may be complicated, unclear and unintuitive. The only way to be sure that a work is in the public domain is to read and understand the domestic legislation and apply the provisions to that work.
While there is no substitute for asking a legal expert or getting to know the law, our [public domain calculators](http://publicdomaincalculators.okfn.org/) project aims to calculate whether or not a work is in the public domain on the basis of automatic algorithms created on the basis of legal research in countries around the world, which may be useful as a guide.
## Why are some things in the public domain? How do they get there?
There are several reasons why something might be in the public domain. For example:
* **Copyright and related rights may expire**. Copyright is a temporary right granted to anyone who creates a work (whether this is a novel or a film, or a photograph on their phone or a scribble on the back of a napkin). Copyright and other related rights usually expire after a certain period – e.g. a certain interval after the creator’s death, or after a work is created or made available. For example, in many countries copyright expires 70 years after the death of the author for literary, dramatic, musical and artistic works, 50 years after the making available to the public of sound recordings, performance, and other neighboring rights, and 15 years after the compilation of a dabatase (only in Europe).
* **Some things are not copyrightable**. For example some things do not qualify as works under copyright law (e.g non-original works, facts, formulas, algorithms or ideas). In some countries some works are exempted from copyright, e.g. official documents and legislation.
* **Some works may be voluntarily placed into the public domain**. There are legal mechanisms (such as the [Creative Commons CC0](http://creativecommons.org/choose/zero/) license) which may allow users to waive rights or dedicate works to the public domain in certain jurisdictions.
## What are the public domain calculators?
The public domain calculators aim to make it easier to find and identify public domain works in countries around the world. In order to do so, each calculator implements an algorithm to determine whether or not a certain work is in the public domain, given certain details such as date of publication, date of death of author, and so on. You can learn more about them on
## I have a digital copy of a work which is in the public domain. Can I reuse it?
Not necessarily. There may be rights in the digital reproduction. For example a photographer may take a picture of a sculpture that is in the public domain, and will have full rights in the photograph they have taken. Some parties may argue that rights subsist in other kinds of digital copies. In the US the [Bridgeman v. Corel](http://en.wikipedia.org/wiki/Bridgeman_Art_Library_v._Corel_Corp.) case ruled that unoriginal reproductions of public domain works could not be copyrighted. In other countries originality is not the only threshold (e.g. the [Sweat of the Brow](http://en.wikipedia.org/wiki/Sweat_of_the_brow) doctrine). If you wish to reuse a public domain work the best thing to do is to look for an explicit rights statement granting permission to reuse the work.
## How can I use a public domain work? What am I allowed to do with it?
A work in the public domain is not subject to any rights (except for the moral rights in certain countries), you can therefore do anything you want with it, provided that by doing so you do not infringe any other body of law.
## Where can I find works that are in the public domain on the internet?
There are many places to find public domain works, including:
* websites of cultural heritage institutions (museums, galeries, libraries, archives, etc) are a significant source of works which are in the public domain
* domain specific collections of works by certain artists, authors or musicians
* online collections such as the [Internet Archive](http://www.archive.org), [Wikimedia Commons](http://commons.wikimedia.org/), [Project Gutenberg](http://www.gutenberg.org/wiki/Main_Page), and lots and lots of other places
We are currently [collecting links to such collections](http://ckan.net/group/publicdomain), and we would like to systematically add these to [Public Domain Works](http://www.publicdomainworks.net).
## How can I put a digital copy of a public domain work online for people to use?
To put a public domain work online:
* **Upload it somewhere** – e.g. your personal website or on a larger site such as the [Internet Archive](http://www.archive.org) or [Wikimedia Commons](http://commons.wikimedia.org/)
* **Use an appropriate legal tool to explicitly let people know that they can reuse it** – e.g. the [Creative Commons Public Domain Mark](http://creativecommons.org/publicdomain/mark/1.0/) or [CC0](http://creativecommons.org/choose/zero/)