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 (OS versions 8 and 9) 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' ("PowerPlant object"—a general view description), 'CTYP' (custom widgets), and Mcmd (used for dispatching menu-related events). Later it was ported to also support MacOS X development with a single code base.[1]

After Metrowerks was acquired by Motorola, then spun out as part of Freescale Semiconductor, PowerPlant and the rest of the CodeWarrior desktop development tools were discontinued.[2]

During its heyday from the mid-1990s until the early 2000s, PowerPlant was the most popular framework available for Mac programmers,[1][3][4] replacing both the THINK Class Library and MacApp as the premier object-oriented toolkit for the MacOS; however, the transition to MacOS X was rather difficult for many PowerPlant programmers.[citation needed] In 1997, there was no plan to port PowerPlant to the Yellow Box API found on Rhapsody, a radically different API that would become Cocoa, the official MacOS X API.[5] Instead Metrowerks plan was to port PowerPlant using Codewarior Latitude, a Mac to UNIX porting library they acquired recently.[6] In 2000, as Apple revised its transition plans, PowerPlant was ported to Carbon, with the Aqua user interface on MacOS X, offering a solution for developers wanting to support the new operating system.[4][7]

A new version, PowerPlant X, was introduced in 2004 as a native Carbon framework, using Carbon Events but never became as popular on Mac OS X as PowerPlant had been on Classic Mac OS.[8]

In February 2006, the PowerPlant class libraries were released as open source under the BSD license hosted on SourceForge.[9] Although it could theoretically be recompiled for x86-64 Macs, it is Carbon-dependent and therefore can only be used in 32-bit mode, which preclude its use for software to run on macOS Catalina or later as 32-bit application support was dropped by the system.[10]


  1. ^ a b "The Benefits of Using PowerPlant™" (PDF). November 2005. Archived from the original (PDF) on 24 September 2015.
  2. ^ Handy, Alex (15 August 2005). "Metrowerks plans to ax CodeWarrior for Macintosh". SD Times. No. 132. p. 1.
  3. ^ Sellers, Dennis (2 May 2002). "CodeWarrior for Mac OS, Version 8 due May 31". Macworld.
  4. ^ a b Turner, Mark (March 2001). "Carbon: An Essential Element of MacOS X". MacTech. Vol. 17, no. 3. p. 58-61.
  5. ^ Mark, Dave (November 1997). "CodeWarrior Rhapsody Update, Part 2 and a Quick Look at WarriorWorld". MacTech. Vol. 13, no. 11. p. 49-51.
  6. ^ Mark, Dave (May 1997). "Greg Galanos and the Mac Developer's Roadmap". MacTech. Vol. 13, no. 5. p. 64-72.
  7. ^ Atwell, Richard (July 2000). "Arnold goes to WWDC". MacTech. Vol. 16, no. 6. p. 110-111.
  8. ^ "Middleware and Section 3.3.1". Daring Fireball. 30 April 2010.
  9. ^ "PowerPlant Frameworks". SourceForge. 2 January 2014. Retrieved 24 August 2021.
  10. ^ Stat, Nick (12 October 2019). "Why macOS Catalina is breaking so many apps, and what to do about it". The Verge. Retrieved 24 August 2021.