A copyright protects an original work of authorship by giving the copyright holder a monopoly on the right to reproduce, sell, publicly display, publicly perform, adapt or license it. Although copyright law applies equally to software algorithms and other works of authorship such as musical compositions, the application of copyright law to software is unique because of the nature of software itself.
What Software Copyrights Protect
For software to function, both source code and object code must be created. Although source code is the more fundamental of these, a software copyright protects both. Software copyrights also protect screen displays generated by the software. In addition, software copyrights protect derivative works. This means that you cannot bypass someone's software copyright simply by adding additional source statements or making corrections to existing code.
Ideas Versus Expressions of Ideas
Copyrights protect the expression of ideas, not the ideas themselves. This means that copyright law does not protect the procedures, processes, systems, methods of operation, concepts or principles. The fact that someone else has already created software for a specific brand of e-book reader, for example, doesn't prevent you from creating another type of e-book reader software, as long as you don't copy the algorithm used in that product. Patents, in contrast, protect the ideas themselves, and the U.S. Patent and Trademark Office sometimes grants patents that protect software.
End-User License Agreements (EULAs)
Although copyright licensing has been prevalent for a long time, the proliferation and diversity of software has resulted in an increase in the complexity and diversity of software copyright licenses. When you use software, you are typically required to agree to am End-User License Agreement, or EULA. Although many users do not even read the EULA, these agreements often contain restrictive terms. For example, they may prohibit the user from criticizing the product in online forums; require the user to agree to forfeit online privacy rights, or prevent the user from using the product in combination with the products of another vendor.
Works For Hire
A lot of software is created by software company employees. If the employer wants to own the copyright on any software created by its employees in the line of duty, it needs to include a "work for hire" clause in a written employment agreement. Under a work for hire clause, the employer becomes the copyright holder as soon as the work is created -- even the creator must obtain a license from the employer before using the software.
Software is often downloaded from the Internet. If you upload or download an unauthorized copy of copyrighted software, you are in violation of copyright law. Downloading software from the Internet is not like buying a second hand book. When you buy a second hand book, you are purchasing the book, but you aren't creating a new copy of the book. When you download software from the Internet, you are creating a new copy of the software. The Digital Millennium Copyright Act requires Internet service providers to remove infringing material from their systems upon the complaint of a copyright holder and, in some circumstances, to ban users who repeatedly infringe others' copyrights.