According to the official website, GNUstep is:
GNUstep is a free, object-oriented, cross-platform development environment that strives for simplicity and elegance. GNUstep is based on and completely compatible with the OpenStep specification developed by NeXT (now Apple Computer Inc.) as well as implementing many extensions including Mac OS X/Cocoa.
The site is looking for developers to write and port applications to GNUstep so that it can be enhanced to make it a great experience for users.
This is, no doubt, a great opportunity for developers who would like to make headway in Linux programming. GNUStep developing would be an ideal platform for them to showcase their skills and grow with the community of other talented and experienced developers.
Here are some links to know more about GNUStep: