Two weeks before I had to leave for Maker Faire Bay Area 2013, I decided it was time I built an enclosure for the PiPad. I'd been helping a guy in the Shed Tech Support queue that needed some help ...But I think I would replace the Raspberry Pi with an Improv board.
The Improv is a modular engineering kit that comes with a CPU card and a separate feature card to connect it to. The CPU card powers the device while the feature card provides convenient access to the on-board capabilities of the CPU card through a variety of ports and pins on it.
This unique design allows one to have multiple CPU cards for different projects, upgrade the kit by ordering new CPU cards for additional features or feature cards for different sets of ports and off-board components.
Improv comes pre-installed with the Linux-based Mer operating system. We chose Mer because it has been designed specifically for device development, has a thriving community of both companies and enthusiasts and has a proven open governance model directing development. You aren't locked into this, however: you can install the operating system of your choice.