why the two partition manager apps look similar

I found easeus partition manager and partition wizard look so… almost the same style oriented with software interface and site design, and features.
My friend told my easeus partition manager was better, and the price is 50% discount now. But when I tried to search it, I find so many information look so similar…
Finally, I bought partition wizard. Confused! Both of them are from one company?
You may find the similar sites here
easeus partition manager http://www.partition-tool.com/
partition wizard http://www.partition-wizard.com/index.html