GNUstep is a cross-platform, object-oriented framework for desktop application development. Based on the OpenStep specification originally created by NeXT (now Apple), GNUstep enables developers to rapidly build sophisticated software by employing a large library of reusable software components.
GNUstep is an object-oriented tool development kit and a graphical development kit. GNUstep is not a desktop or an operating system clone. It is not a distribution of Linux, FreeBSD or any other operating system now, nor will it be in the future.
While the GNUstep project itself is not a desktop project, many GNUstep applications have been written to provide a powerful user experience for working on your computer. These include our workspace manager, GWorkspace, and mail client, GNUMail. GNUstep does NOT have a window manager. You can use any window manager you want, although we recommend that you use WindowMaker for a better experience.
In addition to the OpenStep API, GNUstep also implements many additional classes and methods, some from the Cocoa API for the sake of compatibility. GNUstep is written in the object-oriented language Objective-C, a superset of C which adds object-orientation to C. Objective-C is very simple, yet very powerful. GNUstep also includes bindings to other languages such as Java (JIGS) and Ruby (RIGS).
GNUstep provides an excellent, mature framework for writing good applications. There's good anecdotal evidence that OpenStep developers have written very complex commercial applications in weeks or months, rather than years (or often, never) in the case of other development environments. Using the visual interface modeling application, you can construct a decent user interface skeleton in a day or so with no coding.
To learn more about the GNUstep project please visit booth 66.