navX-MXP libraries for use with the RoboRIO Libraries from WPI are available in each of the languages/development environments commonly used to development FIRST FRC robot applications:
These libraries provide access to navX-MXP via SPI, I2C and USB and UART – as well as USB and I2C interfaces to navX-Micro, and USB Interfaces to VMX-pi.
[Update: 1/8/2020 – Version 3.1.400 is now available – which is compatible with the FRC 2020.1.2 (Kickoff) Release. For more details on installation, see the page corresponding to your chosen development language.]