ManyMouse is a library that abstracts the handling of multiple mice input into a tiny, cross-platform API. It is meant to be used with games and non-traditional applications with unique input needs. On most platforms, it can at least make all USB mice available, but in many cases can make serial mice and built-in laptop trackpads available too.
Places ManyMouse is known to be used:
ManyMouse is licensed under the zlib license. This means you can statically link it into a closed-source application and otherwise manipulate it however you like, without a warranty. I appreciate credit when you use it, but don't require it. I find this code useful, and hope you will, too.
Just about everything you need to know is here.
Downloading with Mercurial:
ManyMouse's source code may be downloaded using Mercurial (aka: "hg"). Hg allows you to get up-to-the-minute fixes and enhancements; as a developer works on a source tree, you can use hg to mirror that source tree instead of waiting for an official release. Please look at the Mercurial website for more information on using hg, where you can also download software for Mac OS X, Windows, and Unix systems.
Here is the web interface to ManyMouse's Mercurial repository.
To download ManyMouse via hg:
hg clone http://hg.icculus.org/icculus/manymouse/
Page maintained by Ryan C. Gordon.