1. Install GNUstep

sudo apt-get install gnustep gnustep-devel

2. Write hello world program, and save as hello.m

#import 
     
      int main (int argc, const char * argv[]){        NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];        NSLog (@"hello world");        [pool drain];        return 0;}
     

3. Set GNUstep compile enviroment

. /usr/share/GNUstep/Makefiles/GNUstep.sh

4. Compile 

gcc hello.m `gnustep-config --objc-flags` `gnustep-config --objc-libs` -lobjc -lgnustep-base -o hello