Boggle

The gameplay of Boggle, as described in the Bago help file:

The object is to make as many words as possible by following a continuous path through adjacent letters in the rack. (Diagonal counts as adjacent.) The path need not be straight, but each letter in the path can only be used once. Only words of 4 or more letters may be used. If one can form several words by the addition of suffixes, all the words will score. For instance, if you find RATE, RATES, and RATED in the rack, you may include them all in your list. Each round is usually 3 minutes long.

Boggle implementations have been especially popular in Windows.

Boggle Implementations
Boggled
Boggled
Bago
Bago
BogOut
BogOut