Logical Desktop is a desktop environment for GNU/Linux that is different.
Examples of desktop environments are KDE, Gnome, the Windows interface, etc.
In Logical Desktop, like in all desktop environments, you work by composing actions made of one verb and one or more objects (e.g. "Print" is the verb, and the objects are the printer, the files to print, and the program used for printing).
Logical Desktop is how you specify those things: 1) in any order 2) with automatic hiding of the things that don't make sense.
1. In any order: Logical Desktop enables you to specify your action with many possible styles of interaction (file-oriented, task-oriented, program-oriented, device-oriented). Logical Desktop can do that because it treats verbs and objects with complete symmetry and uniformity: you can select both verbs and objects, and in any order.
2. With automatic hiding: Logical Desktop is more intelligent than traditional systems because it hides the unnecessary things while you are composing the action. More precisely, Logical Desktop hides those verbs/files/devices/programs that make no sense with the current selection.
Combining this with the previous point (that you can select anything in any order), we obtain a very powerful mechanism: if you select a verb first, the objects that don't make sense with it are hidden; if you select an object first, the verbs that don't make sense with it are hidden.