These are wheels that have 2 Degrees Of Freedom, allowing them to move in more directions than forward and back.
This allows for design of a based that can move in the X and Y directions without needing to turn, and also rotate while maintaining a straight line - giving the mobile base a full 3 degrees of freedom.
I am still researching into who actually developed them - I know there has been more than one attempt to patent them.
Time to build your own robot! Using a Raspberry Pi with parts and some time, you can use my book to learn how to make and program a robot with automatic behaviours.