I was looking into the different feature detectors/ descriptors for OpenSfm. I saw that there is Hahog but I couldn't tell what this was. I looked at the source code and it appears to call Sift in it a couple of times. Also, I saw somewhere that it was recommended to try using Hahog instead of Sift because they get the same results.
Does this mean Hahog is actually based on Sift? If not, what type of license is Hahog released under (presumably BSD)?