UUIDTools was designed to be a simple library for generating any of the various types of UUIDs. It conforms to RFC 4122 whenever possible.
UUIDTools::UUID.md5_create(UUIDTools::UUID_DNS_NAMESPACE, "www.widgets.com") => #<UUID:0x287576 UUID:3d813cbb-47fb-32ba-91df-831e1593ac29> UUIDTools::UUID.sha1_create(UUIDTools::UUID_DNS_NAMESPACE, "www.widgets.com") => #<UUID:0x2a0116 UUID:21f7f8de-8051-5b89-8680-0195ef798b6a> UUIDTools::UUID.timestamp_create => #<UUID:0x2adfdc UUID:64a5189c-25b3-11da-a97b-00c04fd430c8> UUIDTools::UUID.random_create => #<UUID:0x19013a UUID:984265dc-4200-4f02-ae70-fe4f48964159>