Creative works such as books, paintings, films, sound recordings, photographs, sculptures and architectural works are automatically protected by copyright.

Copyright is an exclusive right that means that for a certain period of time, the creator or whoever else holds the copyright controls how the work may be copied. After this limited period, the work falls into the public domain. This means that anyone can copy it, share it and do all the things that previously only the creator or the rights holder could do.

So for example, a public domain image can be freely reused in a collage, a public domain sound recording can be freely remastered or incorporated into new sound recordings or into new films, public domain texts can be freely translated or they can be incorporated into new editions and so on. With rights of digital networks and devices such as computers, mobile phones, media

players and book readers, public domain works can be endlessly copied for zero cost. This means that the past wealth of cultural works that have fallen into the public domain are free from anyone to enjoy, reuse or build upon. But how do we know whether or not a work is in the public domain?

So there are many international and multinational copyright agreements and copyright organisations that exact details of copyright law vary from country to country. Different countries have different legal systems and traditions and copyright laws reflect these differences.

For example, in Hong Kong copyright lasts 50 years after the death of the author, in France it is 70 years after and in Mexico as of 2003 copyright lasts for 100 years after the author dies. Hence, different works are in the public domain in different countries.

While we speak of the public domain, there are really many different public domains which are determined by the nature and duration of different national copyright laws. In order to make it easier to find and identify public domain works, we are building a set of public domain calculators. Each calculator says whether a given work is in the public domain in a given jurisdiction.

Each calculator requires input from legal experts to represent the copyright laws of a certain country in a flow diagram. These flow diagrams can help you determine whether or not a work is in copyright or in the public domain in each country.

With the assistance of a community of legal experts in each country, errors can be spotted, details can be added and the flow diagrams will become more accurate over time. Flow diagrams are used to create the computer software that runs the public domain calculator.

With the calculators and certain basic details, such as the date of death of the author of a given work, we can automatically determine which works are in copyright and which works are not. With lots of information about works, such as can be found in library catalogues, we can start to build up a better picture about which works are in the public domain for a given country.

This will help to make it easier for everyone to find out which works they are allowed to freely copy, reuse and incorporate into new works. The public domain calculators can provide information and guidance to existing online sources for public domain works, such as Europeana, the European Digital Library, Project Gutenberg,

Wikimedia Commons, the Internet Archive, the websites of libraries and archives and countless other sources. It will help make it easier for anyone to find, use and enjoy the vast and expanding wealth of cultural works that our laws open up for the public.

If you'd like to get involved, we need help with a whole bunch of things. First of all, we need help in creating, reviewing and publicising the public domain calculators. Second, we need help publicising the public domain and why it's important and what you can do with it. And lastly, we need help with projects that use the public domain calculator to do something really concrete and useful, such

as our public domain works database or digitising public domain material and putting it online for others to get access to. If you want to get in touch, just email us at info at OKFN dot org. That's info at OKFN dot org.