The Zoomer is a type of PDA. Zoomers all use GEOS for their OS and are / were produced by numerous different companies and are thus found under numerous different names. The "classic" Zoomers are known as the Z-7000, the Z-PDA, and the GRiDpad and were made by Casio, Tandy, and AST respectively. Newer Zoomers include HP's OmniGo models, Hyundai's Gulliver (which may not have actually been released to the general public), and Nokia's Communicator line of PDA / cell phone hybrids.