Oscar automatically adds things to your grocery list when you run out. You just scan the item's barcode on its way into the trash.
Here's a video about it!
Getting Started: Hardware
That said, there's no reason Oscar shouldn't work with other hardware.
Getting Started: Software
To install Oscar, run the included
install.py as root on the target system. It
will walk you through the process of setting up any API accounts you'll need, and
then it'll install the software.
I haven't really tested that install script, so let's cross our fingers together.
Thanks to the awesome CloCkWeRX for picking up my slack now that I don't have a Raspberry Pi to test on anymore.