Scissor doors, also called Jackknife doors or Lambo doors, are automobile doors that rotate up and forward on a hinge near the front of the door.
This form of door was first introduced in the Alfa Romeo Carabo concept car, designed by Marcello Gandini. Gandini used the same doors in the Lamborghini Countach whose wide chassis mandated this unusual door configuration. The design was carried forward to the Countach's successor, the Lamborghini Diablo. The only current Lamborghini in production which uses this design is the Murciélago.
This design combines some of the advantages of a conventional door and the traditional gullwing door. The door can open upward rather than outward, which is important in wide cars. The hinge is in a similar location as a conventional door, so a convertible version of the car is not prevented by the door design.
The disadvantage is that the door still impedes access/egress much more than a gullwing and, in some cases, more than a conventional door.