It's quite a common oil in the UK as we grow it over here and fairly cheap. It isn't genetically modified either which is a reason some people avoid canola. I use it in recipes in place of sunflower.
People say that rapeseed oil is simply canola oil, but it's more complicated than that. Canola comes from a variety of rape whose oil has had the eruric acid and other things (conventionally) bred out of it. This product was created in Canada (hence the name) and bears little resemblance to wild rapeseed oil. Different appearance, different taste, different composition.
As Saponista points out, rapeseed oil is popular in the UK where a lot is produced, sometimes as a cold-pressed product. You can also buy such a thing on Amazon in the USA. I don't know if these are low eruric acid varieties like canola (< 2%) or more like wild rapeseed oil.
For what it's worth, Soapcalc's entry for "rapeseed oil, unrefined" is definitely NOT canola oil.