The code is released under the GNU General Public License.
This is a Kalman filter library for any microcontroller that supports float math.
It can also be used with Arduino, simply copy the folder to your library folder.
My assignment I wrote back in High School regarding Kalman filter can be found here: http://www.tkjelectronics.dk/uploads/Kalman_SRP.zip.
For more information see my blog post: http://blog.tkjelectronics.dk/2012/09/a-practical-approach-to-kalman-filter-and-how-to-implement-it or send me an email at kristianl@tkjelectronics.dk.