Over at the Honeybadger blog, Starr Horne wrote an interesting article on the different types of UUIDs and ULIDs.

UUIDs are and will continue to be the standard. They've been around forever, and libraries are available in every language imaginable. However, new approaches are worth considering, especially as we enter a world that's increasingly run by distributed systems. New unique-id approaches may help us solve problems that weren't prevalent at the publication of RFC4122.