Free Focused Scroll is a project to implement an open source driver for Apple PowerBooks. The project was started as an alternative to SideTrack (which isn't free) and an improvement upon iScroll2. It achieves its advanced features by running the trackpad in what is called 'absolute' mode. This means that the driver can tell exactly what part of the pad your finger is touching. The Apple driver (and iScroll2) both run the pad in 'relative' mode, and while that facilitates a simpler driver because the pad does most of the work, it is very limiting of what you can do.
Most notably running in 'absolute' mode allows the driver:
The driver is NOT designed for use with the new 2005 PowerBooks nor is it based upon the newer driver for them. It is entirely based upon the original Darwin ADB trackpad driver with the information for how to activate `absolute' mode taken from the ScrollPad project. The preferences daemon and the two-finger scrolling code is taken from the iScroll2 project as we didn't really want to reinvent the whole wheel. At some point we intend to remove the iScroll2 scroll code, though. We believe it is possible to make the code much better if it utilises absolute coordinate information instead of just relative movement.
Do not worry about installing this driver, though. The installer will only allow it to be installed on compatible Macs and the uninstaller is pretty foolproof. Plus it's small!