Once software is developed and is ready to be sold, it can be copyrighted. Copyright protects the expression of an idea, not the idea itself. For example, a person could not copyright the idea of a computer database management system but could copyright the structure and content of a database software program that expresses the idea of a database system. Court decisions appear to have limited copyright protection for some features of software. Microsoft Corporation's Windows software program contained a GUI nearly identical to Apple's.
Patent law supplies another avenue of protection for software companies.
A patent protects the idea itself. It is often an unattractive option, however, because it takes a significant amount of time, usually two years, and money to obtain a patent from the U.S. Patent and Trademark Office. The patent process is complicated and technical, with the applicant required to prove to the Patent and Trademark Office that a patent is deserved. Because the shelf life of a software program is often short, seeking a patent for the program is often impractical. Trademark law protects the name of the software, not the software itself.