CameraTransfer is a free software (GPL license) that is used to get pictures from a digital camera.
CameraTransfer is developped in Objective C (a C object oriented language) and uses the GNUstep framework.
GNUstep is an object oriented developpement environment.
GNUstep is based on OpenStep specifications created by NeXT (now Apple). The additions made to Cocoa (MacOS X) will be added for compatibility reasons.
GNUstep is written in Objective-C, an object oriented language based on C, with few additions to make it object oriented. The Objective-C language is very simple and powerful, and a GNUstep interface is still created for Java.
libGphoto2 is a library used to access files on a digital camera. Today, libGPhoto2 knows more than 400 digital camera models.
CameraTransfer uses libGPhoto2, thus, all new cameras known by libGPhoto2 will be known by CameraTransfer.