IBMs Workpad series was nearly identical to PDAs manufactured by Palm. The main difference were color and logo on the casing.
WorkPad (rebadged PalmPilot)
WorkPad 20X (rebadged Palm III)
WorkPad 30X (rebadged Palm IIIx)
WorkPad c3 (rebadged Palm V/Vx) thin, sleek, metal case
WorkPad c500 (rebadged Palm m500) thin, sleek, metal case
WorkPad c505 (rebadged Palm m505) thin, sleek, metal case