Programmers find it much simpler to create automatic GUI creation tools when using a standard framework, since this defines the underlying code structure of the application in advance.
[citation needed] Apple Computer developed one of the first commercial application frameworks, MacApp (first release 1985), for the Macintosh.
Another notable framework for the Mac is Metrowerks' PowerPlant, based on Carbon.
Free and open-source software frameworks exist as part of the Mozilla, LibreOffice, GNOME, KDE, NetBeans, and Eclipse projects.
Several frameworks can build cross-platform applications for Linux, Macintosh, and Windows from common source code, such as Qt, wxWidgets, Juce, Fox toolkit, or Eclipse Rich Client Platform (RCP).