Yep, although as I understand it they've worked so hard on it since the Kickstarter I'm not sure how much is still recognisable as the core ETH code. At the very least their software is rooted firmly in the PX4/Lorenz design ethos. One of the guys behind the project is also the author of some very nice PX4 and MAVLink tools which you may well have used: https://github.com/DrTon
[we have a nightmare at work trying to distinguish between original PX4FMU running PX4, Pixhawks running PX4, and Pixhawks running APM codebase in conversations]