Keystone

Keystone or key-stone may refer to: Keystone (architecture), a central stone or other piece at the apex of an arch or vault Keystone (cask), a fitting used in ale casks

==Companies== Keystone Law, a full-service law firm Digital Keystone, a developer of digital entertainment software Keystone Aircraft Corporation Keystone Bridge Company, an American bridge building company Keystone (beer brand) Keystone Camera Company Keystone (gasoline automobile) Keystone (steam automobile) Keystone Pipeline, a crude oil pipeline Keystone-SDA/Keystone-ATS, a Swiss press agency Keystone View Company, a US photo agency Keystone (Berkeley, California), a defunct music club