IBM's name for
OS/2 versions 3 and 4. Will be abandoned because of
Paramount licensing issues.
The distiguishing feature of Warp is its object-oriented WorkPlace Shell on top of Presentation Manager windowing engine. WPS is considered by many the most advanced (though unstable due to M$ collaboration) GUI up to date, especially when enhanced by addons such as Stardock's Object Desktop, which, by the way, also exists for the inferior Winblows product.