DOF PRO is a commercial tool. You may freely download the plugin and try it as much as you want, whenever you want, wherever you want, by whomever you want, while in DEMO mode. In DEMO mode, the plugin is a FULLY FUNCTIONAL VERSION with the exception of being able to apply the filter to your image. Everything works unrestricted, even loading and saving, so that you can understand how this plugin works before you register it. Upon registering, you will receive a personalized license by email, which will switch it to REGISTERED mode. ONE (1) DOF PRO license entitles ANY user to UNLIMITED use of the software, for an INDEFINITE period of time, on ONE (1) workstation ONLY. Currently, there is no floating license option. If you wish to use DOF PRO on multiple workstations such as in a studio environment, multiple licenses are required: one for EACH node.