DxO is running a promotion through February giving away free licenses for OpticsPro 9, its Raw processing software. You'll miss out on the latest camera/lens support and features offered by OpticsPro 11, but hey, it's free.
To get in on the offer you'll just need to provide DxO with an email address to which you'll be sent an activation code. Unfortunately, you won't be able to upgrade the license, so you'll have to buy the latest version outright if you want support for the most recent cameras and lenses. You can check DxO's list of supported cameras and lenses here.