It’s cool to see the “move your mouse between computers” concept become more widely available. I worked as an intern at TideBreak in 2007. Their product PointRight was based on work the founder did at Stanford in 2000. It let you move your mouse from one computer to another:
There was a program called CosmoSynergy in 1996 that lets you share a mouse between computers.
There is a fork of it called "barrier". Using it every day.