This DLL checks if your program is already running and controls what has to be done if this is the case.
What is new is that it not only checks if the processnames are the same, but also checks if the sha512 hashes are the same. If the names are the same but the hashes are not, apparently there is another program with the same name, but now, it will no longer stop your program from running, while still not opening multiple instances!
This DLL is written in vb.NET.