There has been recently news about uses of PX4 (APM/ACM port and James Gopperts post on state estimation control), its time to recap the platform state and to give an overview of the current roadmap. There are a few important hardware highlights:
PX4 as a platform tries to provide more robustness (on the hardware level), more flexibility and a modern software application interface. All this allows to implement new functionality that has been limited so far, most importantly it however decouples the platform (operating system, sensor drivers) from the application software (state estimation filters, controllers).
We're moving from a monolithic block where everything is closely coupled to a design where you have an operating system and apps that have individual functionality. It allows you to mix different apps from different developers and projects, and as developer it makes it easier to write software for it (a POSIX-style API quite similar to e.g. MacOS or Linux and a middleware API somehow similar to ROS, but more efficient).
Therefore besides from the actual PX4 platform (OS, middleware), there is also a complete autopilot stack (in fact by now already multiple controller / filter choices, plus the APM port).
We have by now test-flown all of the onboard fixed wing controller choices, and went out today to test the newly contributed Kalman filter based attitude and position estimator plus fixedwing controller from James Goppert. All in all the flight went well and smooth in manual and stabilized mode and we'll take the plane out for autonomous flight tests this weekend. Now that the core infrastructure is in place and reliable, expect much more progress on the autonomous flight, both from the APM port and from individual developers contributing new controllers and filters.