Text Mode Doom

Open-source hackers find it bizarrely novel to incorporate text-mode frontends for the applications which would traditionally be best suited to a more detailed interactive display. Doom is no exception, and there have been a number of attempts to develop a text-mode front-end for it.

SMMU
The source port SMMU incorporated a DOS text-based renderer.

libcaca
Libcaca is a text-rendering library that can be plugged into a variety of other programs and renderers, including libSDL. Doom was used as a demonstration of the library's novelty. The second image below is from Doom Legacy while the first image may also be from Doom Legacy but there is not enough information in the screenshot to determine if it is.