The Microsoft Windows MultiPoint Software Development Kit (SDK) helps developers create programs that enable the use of multiple mice on a single computer.
This is really neat. It will be a big help if you are working on same-room collaboration systems. It also makes it plausible to port applications to large touch systems like wall displays or tabletop interfaces like the Microsoft Surface. In the past it has been difficult to move an application to a touch-based interface because users keep “stealing” the mouse cursor from each other. Presumably with this SDK you can work around that problem. (Is it just happy coincidence that this is coming out around the same time as the Surface?)
This SDK came out of Microsoft Research but has been transferred to an education products group. There’s currently a single blog post from the team if you want to follow along: http://blogs.msdn.com/multipoint/default.aspx.