Deimos Labs is a wad I started a few years back. Even though it's only a single map, every time I began mapping, I'd say, "No, this isn't how I want it to look," and then I'd start over from the beginning. This happened numerous times, and after studying a myriad of community-recommended wads, I have finally created the wad I envisioned. This didn't really take a few years since I stopped working on it for a long time, but I did have the idea in my head for that long.
The map is quite long (it takes me about 30 minutes to finish it, has a moderate difficulty, and is a techbase-themed map. I wanted to make the base feel and look like it's 'infested', and I believe I accomplished that quite well.
Oh, and just a heads-up: You won't be able to complete the map without jumping. Sorry, old school fans!
id Software, the Doom community
New from scratch
Not taking into account periods of inactivity, about 4 months.
Doombuilder, Doombuilder 2, SLADE, XWE
It's a large map, so there might be some bugs. I had a few friends playtest it and they didn't find any, but if you do, then please report them to me.