A book stack, a way to organize books in a library.

Stack, a data structure based on Last In, First Out (LIFO)

An amplifier stack, as used in guitar terminology

Call stack of a program, also known as a function stack, execution stack, control stack, or simply the stack

Chimney, in the term "smoke stack"

Flue gas stacks, the industrial terminology for an industrial plant chimney

Protocol stack, a particular software implementation of a computer networking protocol suite

Stacks (software), a Dock feature found on Mac OS X v10.5 "Leopard"

Flesh-n-Bone who is also known as "stack"

Stacks (rapper), the stage name of the rapper Yannique Barker.

Stack (geology), a large vertical column of rock in the sea

Solution stack, set of software subsystems or components needed to deliver a fully functional solution

Stack (descent theory), general category-theoretical concept to formalise "pull-back" operations in geometry and algebra

Algebraic stack, a generalisation of scheme and algebraic space in algebraic geometry; a specific type of stack (descent theory)

Brian 'Stack' Stevens, a Cornish rugby player