After a quick visit to http://simplygnustep.sf.net you are met with refreshingly little information for a Linux site. That is because this isnít about Linux. Simply GNUstep isnít your average bloated Linux distribution. It doesnít include GNOME or KDE and doesnít discuss any other software besides GNUstep. Linux is used only to enable your hardware and launch GNUstep (although your favorite Linux applications will most likely run just fine).
By this time you may be wondering, "what is GNUstep?" GNUstep is a platform that matches the Objective-C Object Oriented desktop that Steve Jobs created with NeXT and OpenStep. To my knowledge, GNUstep was started before NeXT returned to Apple, just as the NeXT platform was fading. GNUstep developers wanted a free software version of the OpenStep platform. Fearing that NeXT would fade into oblivion, they wanted to ensure that their favorite desktop would not.
Visit http://www.gnustep.org and http://www.gnustep.net to learn more about the history of GNUstep. To sum up the experience, GNUstep found themselves in great fortune when NeXT was chosen by Apple as the foundation for Mac OS X. Steve Jobs took the great work started with the OpenStep API and called it Cocoa. The result? GNUstep brings Cocoa to Linux and you x86 PC. Well, almost.
Apple has been busy improving the OpenStep API, turning it into Cocoa. The display technology for Mac OS X, called Quartz, uses vector based PDF language to render your view of the desktop. NeXT used Display PostScript but Apple dropped it to improve performance and avoid licensing fees to Adobe. GNUstep uses the original NeXT style PostScript method avoiding licensing issues with the free software GhostScript. The desired result is the same but expect the GNUstep display method to run a bit slower today.
The next difference between GNUstep and Cocoa is that GNUstep has the goal and therefore the burden of matching 100% of the original OpenStep API. Apple started with 100% of the API years ago and has been free to expand it. GNUstep is catching up very quickly for a project that, before today, you may not have known exists. Progress meters on the main GNUstep site indicate that the libraries responsible for the user experience are roughly 80% complete. Developer tools match OpenStep at about 40% completion. As we will soon find out, these percentages, for the OpenStep API give a tremendous amount of functionality.