Triflight is a flight controller firmware optimized for tricopters. Triflight is based on Cleanflight, but the plan for 2017 is to rebase the changes to Betaflight and iNav. After enought testing, the changes can be merged to the respective branches.
If you have found this firmware useful, please consider donating through Paypal or Patreon: https://www.paypal.me/lauka https://www.patreon.com/triflight