This algorithm was created for sdbm (a public-domain reimplementation of ndbm) database library. It was found to do well in scrambling bits, causing better distribution of the keys and fewer splits. It also happens to be a good general hashing function with good distribution. The magic constant 65599 was picked out of thin air while experimenting with different constants, and turns out to be a prime. This is one of the algorithms used in Berkeley DB (see sleepycat) and elsewhere.