If you write software for a computer, or an online application for the Web, or an app for an iPhone, you surely want to protect that work from infringement. After all, code can be stolen. You deserve the benefit of your hard work, and copyright protection can provide you with tremendous benefits. (For a comprehensive discussion of copyright law, see Nolo's Copyright Resource Center.)
It is true that you do not have to formally register your code to get copyright protection on that code. Under American copyright law, the instant your software becomes fixed in a tangible medium; that is, the instant you write it with your fingers; you own the copyright.
However, actual copyright registration provides you with significant advantages, including the ability to easily prove the date of your creation. Indeed, one of the most efficient and cost-effective ways for software authors to protect their work is to register it with the U.S. Copyright Office.
Registration is relatively fast and inexpensive. For the significant benefits copyright provides, it's well worth your time and money.
If you want to stop someone from using or otherwise infringing on your work, you must sue the infringer in federal court. However, in order to do so, you must first have registered the copyright with the U.S. Copyright Office.
If you have to register in a hurry (so you can file your lawsuit), you have to pay several hundred dollars extra for "expedited registration." Not only that, but the formal registration will potentially scare off infringers (especially if you have a note on the bottom of your website with the © symbol).
There is another, more compelling reason to register as soon as possible after you publish the software. All copyright owners may ask for actual damages in a copyright infringement lawsuit. However, if you registered the work before the infringement began or within three months of the date the work was published, you may also be entitled to recover:
This is significant. Because it is often difficult to demonstrate how much the infringement damaged the copyright owner, actual damages awarded can be minimal. And lawyers' fees and court costs in federal lawsuits are expensive.
The ability to obtain statutory damages and attorneys' fees and costs will increase your chances of recovering enough money to make your lawsuit worthwhile.
Finally, early registration can actually help keep you out of court. An infringer who knows that you could recover substantial statutory damages might be more willing to negotiate and settle outside of court.
The U.S. Copyright Office provides a handy guide for the registration of software copyrights. Its website is designed for average people to be able to proceed with registration without an attorney. Also check out Nolo's A Legal Guide to Web & Software Development, by Stephen Fishman, which contains all of the necessary forms and step-by-step instructions to apply for copyright registration.