Why don’t all software products qualify for patent protection?
There are a number of reasons why a piece of software might not qualify. For instance, is the ‘software’ really just a business method? That is, is it advancing technology, or just refining an existing process by using a computer? Was it made with open-source (someone else’s) code? Was it made in a country that doesn’t protect software (many countries explicitly exclude ‘a program for a computer’ from patentable inventions)?
They may also not meet requirements for newness. If it’s a simple thing to code, that many programmers might make independently, the ‘invention’ may be too trivial to award a patent to. Or, it might serve to hinder innovation. When the GIF (graphics interchange format) image was patented, that made it harder for everyone else to use that type of graphic. The PNG (portable network graphic) image format was made almost entirely to work around the patent of GIF images. This proliferation of similar ‘inventions’ makes computer communication, such as using the internet, more difficult because all these things have different standards. If the GIF patent had never been issued, third party programmers would not have to worry about making their products compatible with both formats (read this article to learn more about this particular problem).
You can read the United States’ patent law, 35 USC 101, or on our database Lexis-Nexis. It’s worth reading scholarly articles on the subject, as well – try this sample search for articles on patent protection.