I have used Prayaya before. And I found that Hopedot VOS possess all the features Prayaya has. They both are virtualization softwares that enable users to run a virtual operating system similar to Windows OS directly from a USB drive. But Hopedot VOS is compatible with more softwares and has better performance.
I afraid the biggest difference is that Hopeodot VOS has an advanced version --Hopedot VOS (Security Edition) besides the Standard Edition. The following is from the website:"While in Standard Edition, users can copy files easily between host environment and Hopedot environment. In Security Edition, files and data transafer between these two environment must be imported or exported with management password needed."
As far as I know, another difference is that Prayaya V3 is free now. But I also notice a little difference between the free version and the previous purchased version of Prayaya. Prayaya’s toolbar has become very simple, only retain the “switch” button to switch back and forth between two Prayaya’s system and the host system. That’s why we can’t lock the screen or change to small window mode now.
Hopedot VOS’s trial versions are free to download as well. It allows users to try 100 times and all the features are fully functional. I like this idea of trying a software 100 times but not a month limitation. In this way, I have enough time to know the software better.