The purpose of this project is to provide a Free Software version of the Cocoa/OpenStep APIs available on as many platforms as possible. GNUstep seeks to be source code compatible with Cocoa and OpenStep. GNUstep currently supports GNU/Linux, NetBSD, OpenBSD, FreeBSD, Solaris, Darwin and Windows and should be capable of being built and used on any POSIX compliant UNIX platform which has gcc and/or (soon) LLVM/Clang. GNUstep provides a robust implementation of the AppKit and Foundation libraries as well as the development tools available on Cocoa/OpenStep, including Gorm (the InterfaceBuilder) and ProjectCenter (ProjectBuilder/Xcode).