About This File
You might've heard of MDK, a wacky third-person shooter, released by Shiny Entertainment about 20 years ago. It was a cross between the action of Doom and humour of Earthworm Jim (made by the same folks). To my knowledge, MDK isn't moddable at all. However, Csabo, the author of the infamous XWE, added MDK support to his editor. It can't open all of its data files, but it can cope with the ones that contain the skies (.DTI format). MDK's skies are stored as BMP files in 1804x360 or 904x360 resolution, but they can be converted to the resolution and palette used by Doom and/or its ports without too much distortion. So... ever thought your map could use a new sky?
the guy who created the official tutorials for Doom Builder 2 (AlysiumX on Youtube). id Software for [one of] the best games ever. Shiny for [one of] the best games ever. Everyone who made the editors I used. Mnich from the HecticHQ forums for assuring me that doing this for non-commercial purposes is legal.
An hour or so
XWE 1.16, Doom Builder 2, SLADE 3
They might look a bit crappy, 256 colours, you know.