Binary Fortress (the developers) occasionally runs official promotions where you can earn a lifetime Pro license for free:
If you want to test the full power of the software, Binary Fortress (the developer) offers a of the Pro version. No credit card is required. displayfusion license key free
Here's that article:
Believe it or not, there is a legitimate way to use DisplayFusion for free, but it comes with a caveat. but it comes with a caveat.