final: prev: {
  # tools

  agbcc = prev.callPackage ./agbcc { };

  # roms

  pokegb = prev.recurseIntoAttrs {
    # official (chronological order)

    red = prev.callPackage ./pokered { };

    yellow = prev.callPackage ./pokeyellow { };

    gold = prev.callPackage ./pokegold { };

    crystal = prev.callPackage ./pokecrystal { };

    ruby = prev.callPackage ./pokeruby { };
    ruby-modern = prev.callPackage ./pokeruby { modern = true; };
    ruby-de = prev.callPackage ./pokeruby { german = true; }; # german version
    ruby-de-modern = prev.callPackage ./pokeruby { german = true; modern = true; };

    firered = prev.callPackage ./pokefirered { };
    firered-modern = prev.callPackage ./pokefirered { modern = true; };

    emerald = prev.callPackage ./pokeemerald { };
    emerald-modern = prev.callPackage ./pokeemerald { modern = true; };

    all = prev.callPackage ./pokeall { };
  };
}