Hah! I was going to guess it was a vinca, but I'm not familiar with that particular variegated one. I have the regular version growing happily in a flowerbed in my zone 4 yard. I'm about to invite it to spread, as its filled up the contained bed and is really quite a polite plant (and will grow in deep shade without tons of water, very useful here). I think mine is a vinca minor. If anyone knows better than I, please correct me!