jOOU is filling up the gap with one of Java's most wanted features: The unsigned number types. Incredibly, there seems no simple implementation available for just the four basic unsigned integer types as wrappers: UByte, UShort, UInteger, ULong See also this stack overflow question here: http://stackoverflow.com/questions/8193031/is-there-a-java-library-for-unsigned-number-type-wrappers So I have implemented these four classes, extending java.lang.Number and implementing java.lang.Comparable<?>. Besides, there is a utility class called org.joou.Unsigned with factory methods allowing for creating unsigned wrappers like this: import static org.joou.Unsigned.*; // and then... UByte b = ubyte(1); UShort s = ushort(1); UInteger i = uint(1); ULong l = ulong(1); This was created for http://www.jooq.org, to provide better support for MySQL, Postgres, and other databases' unsigned integer data types.