Dante's Gate

Dante's Gate is a single-level PWAD designed by John "Dr. Sleep" Anderson. In an era when level editing tools were fairly primitive, it distinguished itself by a strong emphasis on theme and mood, as well as by technical soundness. It is now considered an all-time classic.

At least five versions of the map are widely available: The first three WADs replace E1M1; the other two replace MAP02. The level appeared in Maximum Doom as DANTE2.WAD, DANTE21.WAD, and DANTES2.WAD.
 * Version 1.0 (DANTES.WAD), released May 17, 1994.
 * Version 1.2 (DANTE12.WAD), released July 16, 1994.
 * Version 1.666 (DANTE666.WAD), released November 23, 1994.
 * Version 2.0 (DANTE2.WAD), released October 17, 1994.
 * Version 2.5 (DANTE25.WAD), released February 21, 1996.

Secrets

 * 1) North of the exit is a pit with a partial invisibility and a chaingun.  Walking towards the invisibility opens up a secret room in the south-east corner of the pit containing a cacodemon and a switch which lowers the chainsaw platform near the start. (sector 75)
 * 2) Approaching the chaingun mentioned in #1 opens up a secret room in the south-west corner of the pit containing an energy cell and some monsters. (sector 100)
 * 3) North of the crushing ceiling just before the southernmost area (which contains the yellow key in hard skill) is a lion switch which opens a door leading to a room with a blue key and (on hard skill) an invulnerability.  Both the door (sector 347) and the sector immediately after it count as secrets.
 * 4) See #3.  This secret is too narrow to obtain credit for, thus the maximum secrets achievable on this map is 85%. (sector 87)
 * 5) The stairs north-east of the crushing ceiling mentioned in #3 leads to a door leading to a small room containing a box of bullets, a medikit, a zombieman and a revenant.  The eastern wall of this room is a secret door leading, via another door, to a ledge overlooking the yellow key area with 2 imps, a plasma gun (hard skill only) and a supercharge (multiplayer only).  Both the sector immediately after the secret door (sector 166) and the sector immediately before the door to the ledge count as secrets.
 * 6) See #5. (sector 222)
 * 7) The large western area (which contains a building which contains a BFG9000 and the yellow key on easy and medium skills) has a trench in the west containing a radiation shielding suit.  This leads north to the area across the trench.  En route is a short techno floor lamp, across from which is a secret door leading to a room with a medikit, a megaarmor and (on easy and medium skills) a rocket launcher. (sector 214)

Current records
The records for the original map on the Doomed Speed Demos Archive are:

The records for v1.2 of the map on the Doomed Speed Demos Archive are:

The records for v2.5 of the map on the Doomed Speed Demos Archive are:

Things
Dante's Gate contains the following numbers of things per skill level:

Technical information
Version 1.666 of this map was created to accommodate an obscure engine bug in Doom 1.666, which affected floor triggers tagged to multiple sectors.

Inspiration and development
The following additional releases of Dante's Gate have been reported:
 * Version 1.1 (June 14, 1994).
 * Version 2.1 (December 15, 1994).
 * Version 2.2 (July 5, 1995).
 * Version 2.3 (August 8, 1995).
 * Version 2.4 (November 11, 1995).

Trivia
In the readme file for version 2.5, Dr. Sleep lists no fewer than eleven editing tools (and two image processing programs) as having "had a significant effect" on the WAD.