Listing of open-source Inertial Navigation system

Polaris is an Inertial Navigation software developing in Python mostly to use with X-Plane simulator:

INSTK: is a toolkit for Octave/Matlab:

DynamicTrack is an interface to devices that provide dynamic position/orientation:

Inertial Navigation for Robots:

Madgewick sensor fusion:

Gentlenav/MatrixPilot is an IMU system for UDBx boards (found at Sparkfun):

Premerlani’s post about his IMU system: