The attached zip file contains full documentation and source code (both CodeWarrior and KDS) for Version 5 of Freescale's Sensor Fusion Library for Kinetis MCUs.
The 6 and 9-axis Kalman filters have been rewritten from scratch by fusion expert Mark Pedley. The new versions have improved dynamic tracking and at-rest stability. All documentation has been updated, and full implementation details are included. We continue to use the BSD 3-clause software license, so you are virtually unlimited in how you use the library.
I will note that due to the Kalman filter changes, Mark made some changes to the undocumented Kalman filter packets which are utilized by the Windows Version of the Freescale Sensor Fusion Toolbox. This breaks compatibility with older versions of the toolbox. I will be posting a pre-release of the new one immediately after completing this post. The Android version of the toolbox does not make use of the Kalman filter packet, and should be forward compatible - although an updated version of that is in the works as well.
Structure of the new library is very similar to Version 4.22, which was the previous production version. There are changes, but I don't expect anyone to have problems adapting existing projects to the new version of the library. I think you will get improved performance if you do.