Until few years ago, polyurethane was the only option for a finish. Luckily there is WOCA supplier here in Calgary- Magna Hardwood Flooring.
What is WOCA? It's penetrating oil that does not create a plastic film on a wood surface. It's very eco-friendly and your floor will never need to be re-sanded again. Read more here...
Take a look at the file/brochure. More and more businesses are turning towards WOCA as a finish option because re-sanding is wrong. Yes, re-sanding is wrong. I've been sanding floor for quiet a few years now and I can say again: re-sanding is wrong. Imagine that floor on a railway station in London UK (see the brochure), with so much traffic, can they afford (time) re-sanding the floor every 6-12 months? They will need a brand new floor in 2-3 years, is that something they want to do?
For you as a homeowner WOCA Oils might be appealing because they are very eco-friendly, floors are easy to maintain and repair, and again your floor will never need to be re-sanded.
Based on my personal values, expectations and experience, WOCA oils are the most superior finish available and the only finish people should use.
But be prepared, there are limitations: there are colored oils/stains that work on White Oak only. Red Oak can take some light colors. For other types of wood I'll have to use natural oils. It also takes longer for a project to be completed as the oil needs additional 3-5 days to cure. Cost-wise, I charge $5.00/sq.ft. for most of the floors, so it's not much more expensive that a polyurethane option.