To switch the default backend in GNUstep to the corresponding FLAVOR,
enter one of these lines:

* cairo:
  defaults write NSGlobalDomain GSBackend libgnustep-cairo-${BACKENDV}

* libart:
  defaults write NSGlobalDomain GSBackend libgnustep-art-${BACKENDV}

* xlib:
  defaults write NSGlobalDomain GSBackend libgnustep-back-${BACKENDV}
