The "Derby" sometimes goes by the name "Gibson". It is characterised by eyelets for shoelaces that are sewn up on top of the vamp, a construction method that is also sometimes referred to as 'open lacing'. It's a particularly versatile fit pattern and that's why it was adopted for early military footwear, as shown here.
In contrast, the Amerixan "Oxford" features eyelets for shoelaces that are stitched underneath the vamp. T&F Slack Shoemakers offers two different sole options on its "Derby" - lightweight micro soles in a range of different colours, or stitched leather soles.