• The SGI IRIS 4D
  SGI IRIS 4D
  The SGI IRIS 4D series was a line of workstations from Silicon Graphics built in the late-1980s through mid-1990s. They were the first SGI workstations to use the MIPS architecture. The line culminated with the Crimson which was produced until 1997....
  
   line of workstations from Silicon Graphics
• Class 4-D, a classification of the Selective Service System
  Selective Service System
  The Selective Service System is a means by which the United States government maintains information on those potentially subject to military conscription. Most male U.S. citizens and male immigrant non-citizens between the ages of 18 and 25 are required by law to have registered within 30 days of...
  
  
• 4-D (psychedelic)
  4-D (psychedelic)
  4-D, or 3,5-methoxy-4-trideutero methoxy phenethylamine, is a lesser-known psychedelic drug. It is one of the only phenethylamines that contain deuterium, the other being beta-D. It is also the 4-trideuteromethoxy analogue of 2C-H. It may be prepared either as a sulfate salt or a hydrochloride...
  
  , a psychedelic drug
• 4D film, a marketing term for film
• Cinema 4D
  Cinema 4D
  CINEMA 4D is a 3D modeling, animation and rendering application developed by MAXON Computer GmbH of Friedrichsdorf, Germany. It is capable of procedural and polygonal/subd modeling, animating, lighting, texturing, rendering, and common features found in 3d modelling applications.- Overview:The...
  
  , a commercial cross platform 3D graphics application
• 4D (train)
  4D (train)
  The 4D was a prototype double deck electric multiple unit train built for the Public Transport Corporation of Melbourne, the state capital of Victoria, Australia. It remains the only double deck train ever to have run in Melbourne.-Design:Built by A Goninan & Co...
  
   in Melbourne, Australia
• 4-Digits
  4-Digits
  4-Digits is a lottery in Singapore and Malaysia. Individuals play by choosing any number from 0000 to 9999. Then, 23 winning numbers are drawn each time. If one of the numbers matches the one that the player has bought, a prize is won. A draw is conducted to select these winning numbers...
  
  , a lottery in Malaysia and Singapore
• Air Sinai
  Air Sinai
  Air Sinai is an airline based in Cairo, Egypt. It operates as a 'paper-airline' for parent company EgyptAir under a "wet lease"-like agreement.-History:...
  
  , IATA code
• 4th Dimension (software)
  4th Dimension (Software)
  4th Dimension is a relational database management system and IDE developed by Laurent Ribardière. 4D was created in 1984....
  
  , a database program
• 4-D (The X-Files)
  4-D (The X-Files)
  "4-D" was the fourth episode of the ninth season of The X-Files science-fiction television series created by Chris Carter.-Plot:At the beginning of the episode, FBI Agent Monica Reyes is monitoring Erwin Lukesh, who is suspected of being a psychotic killer who cuts out his victims' tongues. In...
  
  , an episode of The X-Files
• 4D, a photo print size for digital cameras
• Metal Fight Beyblade 4D, the third season of anime series Beyblade

See also

• D4 (disambiguation)
• Fourth dimension (disambiguation)
  Fourth dimension (disambiguation)
  -Science:* Four-dimensional space, the concept of a fourth spatial dimension* Spacetime, the unification of time and space as a four-dimensional continuum* Minkowski space, the mathematical setting for special relativity-Literature:...