Presenting Mathematical Concepts on the World Wide Web
Intellectual Property Rights ... and Wrongs

The public domain contains:

• everything that is not protected by copyright or other intellectual property law;
• in other words, everything that may be used by anyone without permission.

Ideas are not subject to copyright; only their expression is protected.

Similarly, none of the following are subject to copyright:

• concepts, discoveries, methods, principles, procedures, processes, systems, theorems;
• work that the legal owner has placed in the public domain; and
• work in which the copyright has expired.