Twenty years ago, copyright primarily evoked music, film and literature. As each of these became easily mass producible, the right to stop people from copying became more important. Although, music, film and literature are probably the most well-known, copyright can protect music, sound recordings, software code, books, statues, paintings, photos, websites, etc. The U.S. Copyright office has published a very general summary of copyright that you may find useful.
The test for copyright infringement typically requires (1) a valid copyright in the original work, (2) actual copying, and (3) substantial similarity between the original and the copy (your mileage may vary on this part depending on your particular court).
For music, film and literature this can be a fairly straightforward analysis. Take Beyoncé's recent infringement dispute over her inexplicable hit (at least I can't explain it) "Drunk In Love."
A Hungarian singer named Mitsou alleges that Beyoncé sampled the yodeling you hear in the clip from the opening of "Drunk In Love." The original of Mitsou's song is so awful, I couldn't get through the whole thing to find the section that was allegedly lifted. Beyoncé's version isn't much better. But there you go, copyright doesn't care how nauseating the original or the copy: only whether there was copying and similarity. If Mitsou's work was published, she can show copying through access and similarity. Really someone would simply need to put in earplugs (to take the edge off), copy the applicable sections and play the clips next to each other. Showing that the changes in pitch and tone are easily accomplished would help as well.
Maybe you can hear the allegedly infringing sections? See if you can listen longer than the one minute I could:
Moving on from people fighting about bad art to something useful: "What about software infringement?"
The analysis is more difficult with software. In software you have both a user interface and a backend for each program. While the user interface may be subject to copying by the general public, the backend is not. Contrast this against what programmers often value in their software. Many software developers I have talked to are more interested in protecting the guts of their program than the aesthetics of their program. If this rings true for you, the only people with access to the code for the backend of your program are insiders — so copyright might not be well-suited as your only protection. You may need to look to patent instead. If the value of your software is in your user interface and design, then copyright may be well-suited to your goals.
I have found that most software developers are best protected by a combination of patent and copyright (and a touch of trade secret as well). Besides, you can register a copyright online directly with the U.S. Copyright Office for $35, so the bigger question is why not add a copyright registration to the mix?
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
