Just to let you know....
Around 2 weeks ago I saw the main developer of Proview (version 5.1.0-4) has support for the Gertboard and the PiFace.
I only have a Gertboard.
I compiled the Proview source (haven't tried the standard deb) on the Pi and the basics are working.
I have some issue with /dev/mem for GPIO mapping and can only run as root at the moment.
With the tools from Gordon is it possible to use the AVR, (3.3 Volt) as well.
For a strange reason I need to upload the sketch every time after a reboot.
Please keep in mind. The Pi, Arduino, Gertboard and the PiFace are for fun and educational purpose.
Proview is a professional Proces Control System normally running on x86.
If you want to give Proview a try run it on a x86.
This picture shows a part of the production line in Sweden, where the whole production line are controlled and supervised by over 500 Proview systems.
http://www.proview.se/v3/images/steel.jpg
The only thing I want to say, don't judge Proview while using the Pi.