Useful to mention that OpenPicus has little to do with Arduino the way it is presented here.
Except for the great energy put in coming up with cool solutions which both of the camps share !
OpenPicus is based on the Microchip PIC architecture, and supports its own IDE to run on Windows.
This special OpenPicus IDE is designed to shield the user from the complexity of getting down to the bare bones level code, at the expense
of understanding every detail in the underlying code.
While Arduino boards employ the Atmel processors and run the Arduino IDE. That IDE work in a different way,
best found out by testing both.
An interface board has been discussed for Flyport so that you can attach Arduino shields to it and thus take advantage
of those hardware interface boards. But it requires that code is written for the PIC processor to support access to each such shield
since code for PIC processors do not run on ATMel ones and vice versa.
I would say the Flyport and Arduino are two independent processing board development platforms with different approaches.
The two platforms are self-contained design environments in their own right where you can very well mix technologies on signal interface level if so desired.