PowerPlant is an object-oriented GUI toolkit, application framework and set of class libraries for the Classic Mac OS, created by Metrowerks. The framework was fairly popular during the late Classic Mac OS era, and was primarily used with CodeWarrior. It was designed to work with a GUI editor called Constructor, which was primarily a resource editor specializing in UI elements. Constructor used several custom resource types, 'PPob', 'CTYP', and Mcmd. Later it was ported to also support MacOS X development with a single code base.