Using an Apple is like keeping Kosher: the believers would not live any other way, but they cannot eat with members of other religions. Using Unix is like preparing your own meals from recipes in the 'Joy of Cooking': the effort involved initially exceeds the palatability of the results, but experience eventually brings satisfaction. Using Microsoft Windows is like eating at a McDonald's: you can find one anywhere, and the food will keep you going, but it would be sad if there were no other restaurant in town.

— Harold Boas, The American Mathematical Monthly, v. 107, No. 3 (March 2000)