Copyright covers original works of authorship (works of art or science, as Dutch law puts it), like books, plays, films, music and photographs, provided there was some creativity involved in making them. Copyright also covers collections, like anthologies or coffee table books with nicely arranged photographs.

The owner of the copyright in a work has the exclusive right to copy that work, and to make derivative works.

A derivative work is itself a work, but one that depends on another work. A translation of a book is an example, because translating is itself a creative act, but the translation also derives from the original. Subtitles for TV series or a new, updated edition of a textbook are also examples of derivative works.

Getting copyrights

In any country that has signed the Berne convention on copyright, all works of authorship are automatically protected by copyright as soon as they are made. Since 1989, when the US signed the Berne convention, this goes for all major countries, but before that, there were countries where it was necessary to explicitly claim copyright on a work, by adding the © symbol or a phrase like "All rights reserved". Other than in Iraq, Somalia, North Korea and a few other such countries, this is now no longer needed, and we don't do it.

Copyrights can be transferred, e.g. by selling them or giving them away. In many countries, including in Europe, there are some rights that always remain with the author however, such as the right to be recognised as the author and to have your reputation protected with regards to the work.

A very common way in which copyright ends up in the hands of someone other than the author is by work for hire: if you make something as part of your employment, your employer gets the copyright, unless otherwise agreed.

Copyright predates software, but since software is a work of authorship, it is also protected (these days most copyright laws mention it explicitly). Copyright on software covers copying of the program (in whichever form) and making derivative works.

This includes copying from disk to RAM so as to run the program. Dutch law has an explicit exception for this: if you have a legal copy on disk, then you're allowed to copy it to RAM so as to run it.

Exactly what constitutes a derivative work of a computer program or library is a gray area, with little to no case law available. In other words, no one knows for sure what a judge would decide. On the other hand, there is a kind of common understanding of how it should probably work, and people operate on those assumptions with few problems so far.

If you own the copyright for a work, including a computer program or library, then you can give others permission to make copies and derivative works by giving them a license (that's actually specifically mentioned in the law). A license is a specific or general offer of the right to make copies.

For example, Dell™ has a license from Microsoft® to make copies of Microsoft Windows® and install them on the computers they sell. This is a specific offer written down in a contract between the companies. If we put up some code on the web under an open source license, then we are making a general offer – to anyone who wants it – to use our code under those terms.

Note that the End User License Agreement that often pops up when you install software, is – despite the name – typically not a copyright license, since it doesn't give you permission to copy or create derivative works. Instead, it's legally a contract, which is why you have to click OK to accept it.

There are many software licenses out there, including some common Free and Open Source Software licenses. More on these and how to use them is in the next chapter.

Trademark acknowledgements

Dell™ is a trademark of Dell, Inc.

Microsoft® and Microsoft Windows® are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries.