Why should I protect my software ?

When your software is protected, you can stop others from using it without your permission and you can also commercialise it. Furthermore, each specific protection type has its own benefits:

• Copyright enables you to decide on the destination of your software, and to prohibit or authorise reproduction, adaptation, and so on. Copyright protection also allows you to claim authorship of the software development. This way you can license-out your software and make deals with interesting partners.
  Note that software can also be ‘commercialised’ via an open source license. Open source software is software that can be freely used by everyone (under certain requirements), but cannot be used for any further commercial activities. There are different types of open source licenses, and they differ from each other in what they allow you to do in terms of adaptation and redistribution. The more permissive ones give you a wide range of possibilities, while the less permissive ones lock you into an open source logic by forcing you to distribute your contributions under an open source license.
• Trade secrets offer you the opportunity to negotiate with (potential) partners about your know-how. But keep in mind that you have to take measures to keep this information secret, so use a non-disclosure agreement (NDA) or a confidentiality agreement when you negotiate with (potential) partners.
• Your patented software cannot be used by your competitors without your permission. If your software is closely related to or even associated with your commercial products or services, you can make business agreements with your customers or suppliers to use/license your software when they buy your products or services.