navX-MXP includes libraries which are compatible with the RoboRIO Libraries from WPI, and 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, USB and UART interfaces – as well as USB interfaces to navX-Micro and VMX-pi.
[Update: 11/3/2018 – Version 3.1.330 has been released, which is compatible with the 2019 FRC Beta 1 Release 2018.1.1. There are no known issues for release.]