ZDOOM MAP PACKS:
There aren't actually a lot of these. For the most part, people who want to map for ZDoom specifically generally also want to make projects that do a LOT more than just maps - see some of the stuff down below, it starts getting really wild.
Knee Deep in ZDoom
Knee-Deep in ZDoom is an interpretation of Id Software's original groundbreaking production, Knee-Deep in the Dead. The team has focused on expanding the original episode by utilizing the power of Randy Heit's ZDoom port; adding new areas, features, and gameplay devices not possible under the original Doom engine. Knee-Deep in ZDoom is a new experience, but holds strong to the atmosphere of the original.
The original intent of the project was to retell Doom's first episode's story with the modern enhancements ZDoom has to offer, with the justification that id software may have included these things if it was within the capabilities of common consumer hardware during Doom's initial era.
While the majority of the Doom Community enjoyed KDiZD, people found things to complain about. Before the WAD was released, Tormentor677 started hype similar to Action Doom's. Not as many people bought the hype though and many thought it was a bad idea to try and remake Id's levels, so the WAD already had criticism before it was even released. Many people found the use of monsters from the monster resource wad disappointing due to them being overused. Some Doomers thought the level of detail was too high, and the maps were too different from the originals.
Fans of the WAD praised it for the attention to detail and the amount of work that went into the design of the levels. The ZDoom features kept fans on their toes as they discovered new areas and reminisced familiar areas from the classic Doom. It received a Cacoward and a Mordeth award (Released project with the longest development time) at the same time.
Author: Various
Release Year: 2007
Number of maps: 10
Find it here
The Ultimate Torment and Torture
The Ultimate Torment & Torture is a WAD created by Tormentor667 which is a collection of his previous wads (TNT 1 to 4) but revamped for a more enjoyable experience. It enhances former levels in the series as well as finishes off the storyline. TUTNT requires GZDoom or Zandronum to run, due to rendering differences - the credits will crash normal ZDoom, as it lacks Hardware-accelerated rendering.
Author: Tormentor667
Release Year: 2007
Number of maps: 9
Find it here
Thunderpeak
Thunderpeak is a two-level mapset. The first level is a massive power station, heavily infested, which you must restore to working order so as to access the rest of the facility. The reactor core is well guarded by some of Hell's mightiest technodemons. The second level makes you cross a damaged bridge to reach a bunker. Deep underground, you will fight the commander of this demonic taskforce, a walking death machine that can easily terminate you if you are not very, very careful.
Thunderpeak makes good use of ZDoom features to create a majestic, if sinister and oppressive, location. The power plant and the command bunkers are painstakingly detailed, with great attention to texture choice and alignment, interesting architecture, engaging gameplay and stunning visuals. The natural landscape areas around the buildings show a perfect mastery of slopes. The enemy roster features some classic ZDoom monsters such as the shadows from Knee-Deep in ZDoom or the cybruisers from Demon Eclipse (another ZDoom mod), and introduces its own new enemy as the final boss.
Author: Vader
Release Year: 2008
Number of maps: 2
Find it here
Daedalus: Alien Defense
Daedalus: Alien Defense is the sequel to Icarus: Alien Vanguard, but the gameplay was modified to get a greater emphasis on exploration, discovery, and puzzle-solving
Among the strong points of Daedalus are an exclusive set of textures made specifically for it, beautiful scenery and impressive futuristic machinery, and all-around high production value. However, it is easy to become lost in these levels, unsure of what to do next, and the scripted monster respawning can make revisiting levels in search for clues more of a core than was needed.
Author: TeamTNT
Release Year: late 2003, close to 2004
Number of maps: 32
Download
GAMEPLAY MODS:
One of the major draws of ZDoom is that one doesn't need to play Doom the way people did in the 90s. While often that means playing with modern conveniences such as a fixed Z-axis, use of mouse-and-keyboard as in more modern FPS's, and playing in higher resolutions, this also sometimes means playing with gameplay mods that can sometimes rather drastically change how the game is played.
Russian Overkill
I'll just quote the mod's creator:
My answer is pretty simple - hurt hellspawn with most overpowered and ludicrous arsenal in history, such as portable tank cannons, borscht-spewing lazer cannons, medieval maces, slamming ammo packs in monsters face (and then exploding it), fists made of shovels, gesture-coming-true device (TM) (aka. shooting fists), fart mines, inconspicuous superpowered revolvers, huge nuclear-powered energy cannons, miniguns shooting fighter jets that drop bombs!... and of course, nukes coming in all kinds of flavors (sometimes in a moment you would rather not expect a one). And that all is just the tip of the iceberg of madness that is Russian Overkill. If you feel like going nuts after a day of work or school and want the stress out of your system - this mod is for you.
Author: PillowBlaster
Latest Release Year: 2017
Find it here
Samsara
Again, I'll quote the mod's creator, TerminusEst13:
This is a multiplayer project inspired by crossover fighting games, designed to bring these games that people love so much and give them a second life on the multiplayer front, taking the heroes and the weapons and pitting them all aside (and sometimes against) each other. When you play Samsara, you pick a hero from a classic FPS game, spawn in the battlefield with abilities and weapons from their original game, and then proceed to lay waste among all those that stand in your way in whatever iwad or levelset of your choice. Each of the heroes are strictly limited to their own weapons, so you won't have a nonsensical random mash-up of people wielding weapons just not suited for them.
Authors: TerminusEst13 and Ijon Tichy, taken over by Kinsie
Latest Release Year: 2016
Find it here
DemonSteele
Quote TerminusEst13 again:
Designed as a love letter to retro games, 80s/90s anime, and early heavy metal, DemonSteele is a complete and total gameplay overhaul for GZDoom/Zandronum that dramatically changes the flow of the game to an extremely fast-paced hack-and-slash brawler. Wield a razor-sharp sword alongside a mighty gun, and make mincemeat of your foes before blasting away his buddies. Effortlessly dodge through return fire and lop off heads one by one. Or just simply cleave through a crowd in one single dash and swipe.
Gameplay rewards thinking fast and acting faster, with enhanced movement systems (Dodges! Rocket jumping!) and your overall effectiveness based entirely on how many enemies you can plow through in a row with minimal damage to yourself. Kill fast and hard, and you'll be rewarded with a slew of special moves and a bunch of damage...hang from a distance and timidly plink at them bit by bit until they die, and you'll be ill-suited for the challenges ahead.
Authors: TerminusEst13
Latest Release Year: 2016
Find it here
Doom 4 Doom
"Doom(4) for Doom" (D4D) is a gameplay mod that brings the Doom 2016 weapons into the classic Doom maps via GZdoom. It also brings some similar monsters minus the dynamic AI and mobility.
The mod tries to bring the weapons as accurately as possible in looks, behavior and timings. However, the team also took some liberties regarding some behaviors and balance. For example, the "Double Trouble" super shotgun, when ported in here became extremely overpowered, so we completely reworked it. Another instance is the "Gatling Rotator" mod for the chaingun, which makes it now fire explosive rounds.
In D4D all moddable weapons have their respective mods, but once acquired, they dont have "upgrades". All mods are in a fixed upgrade state compared to doom4. When you get "Micro Missiles" for the HAR, they will be "Bottomless" already. Another example, the "Lock on" Rocket Launcher mod, when acquired, will not have the multiple targets upgrade, instead, it stays the way it is when picked.
This mod requires GZDoom to run. It will not run in Zandronum or ZDoom in any capacity.
Authors: DBThanatos et al.
Latest Release Year: 2017
Find it here
Final Doomer
Quote Sgt. Shivers:
FINAL DOOMER is a gameplay mod based around unique weapon sets designed to fit the twin megawads of Final Doom.
There are NINE classes based around TNT, Plutonia, Ancient Aliens, JPCP, BTSX, Hellbound, Alien Vendetta and Whitemare. They all have unique weapon sets based on the megawads they're from. For example, in the chaingun slot the TNT Marine has dual uzis while the Plutonian guy has a Light Machinegun. There's also a regular Doomguy class designed to fit with these classes.
The pistols have infinite reloads, the BFG's work on a "charge" system. Picking up big ammo gives you some charge and when you get enough you get a shot. There's an alternate mode that tweaks it so cell-equivalent pickups give you charges. The classes are balanced around themselves, not each other. There is a config menu that you can use to tweak stuff and holding reload will give you information on your current weapon. Thanks, and have fun!
Authors: Yholl and Sgt. Shivers
Latest Release Year: 2019
Find it here
GMOTA
GMOTA, short for "Go Medieval On Their Asses", is a gameplay mod that emphasizes tackling down monsters with melee weapons and some special subweapons, preferably in the direction of their posterior. Started in 2014, the initial releases were promising, but struggled a bit with direction in gameplay. But after taking in feedback, Kegan reached the much-coveted 1.0 status after four years(!) of development and put out a solid rehaul, smoothing over many of the existing issues and creating an extremely fun gameplay mod.
Author: Combine_Kegan
Latest Release Year: 2019
Find it here
OTHER THINGS:
Calling these map packs does not do them justice, but they aren't gameplay mods either. Check out people who have decided to really bend the engine to their will:
Touhou Doom
There's actually a fair number of DOOM crossover mods. I couldn't pick one, so rather than being fair and picking whatever the best one was, I decided to instead blatantly plug my own work.
This mod is me attempting to see if a Touhou-styled game is viable in this engine.
This is a project that combines aspects of Doom and Touhou, getting more Touhou-like in Episodes II and III.
The mapping isn't very good, (especially earlier on), but I'm happy with many of the things this project has set out to accomplish!
Authors: Untitled (a.k.a. wrsw)
Release Year: 2019
Number of maps: 34 or 39, depending on how you count it
Find it Here
Hell-Forged
Quote the Cacoward ceremony for which it won an award:
Hell-Forged, which began its life as a much older mod called Demon Eclipse, rides a tsunami of style, and maps that appear a touch underdeveloped on an initial clip-through browse turn out to be powered by such an intense, all-encompassing gamefeel that they become impossible to put down. Here is a world made of mausoleums and hellish factories, swimming in blood and fire, the dark industrial atmosphere especially palpable in the later maps. It’s a world where every detail is given weight and purpose, where you can collect whole suits of armor one piece at a time and choose whether to detonate barrels of demonblood as explosives or siphon the blood as ammunition for your rocket launcher. It’s a world filled with unique (as in, literally only appearing once) fragments of lore, such as a templar order’s relic room in the temple where you begin the game, with each surprising new stage detail helping to create the sense of a complete world. Both the lore-building and the huge amount of new interactive content (monsters, weapons, items, explosives, etc.) are made exceptional thanks to Amuscaria’s nearly peerless spriting talents. This year alone, at least four of our other top 20 picks (Eviternity, Paradise, Remnant, Alienated) use monster sprites from Hell-Forged and Demon Eclipse that Amuscaria gifted to the community years ago, and yet Hell-Forged is still packed full of brand new stuff, from towering boss enemies to beautifully rendered male and female player sprites.
Author: Amuscaria (formerly Eriance).
Release Year: 2018
Number of maps:
Find it Here
The Adventures of Square
The Adventures of Square™ is a wacky and wonderful total conversion for the DOOM engine by Bigbrik Games: a new company of level designers, programers, musicians and procrastinators whose impetuous charge is to make things blow up in fun and interesting ways! Lead by James Paddock from 2011, the project began as an ambitious, one-man attempt to bring to life a hidden world of paint, puns and shapism, but soon grew to become the flagship title of a small and dedicated team, including community veterans Xaser, Alfonzo, MTrop, Pavera and Tarnsman. While the first episode is a complete and paid-for experience, it's only a small taster of the crazy delights we have in store for later – so stay tuned!
Square makes extensive use of ZDoom's advanced features in the UDMF format, with a unified approach to its level design, art direction and gameplay. Players can expect to find all the best elements of DOOM's fast and frenetic pace unencumbered by a sharp focus on fun, shapely layouts and free-flowing combat, and with a variety of new and familiar mechanics that build upon this brand of play. The game is made with speedrunning and multiplayer in mind, and features exclusive deathmatch (Square-Off!) maps in which to blast your buddies.
I mean, calling this a Doom Mod is stretching it given the only thing it has in common is the engine, but hey, give this a whirl, it's totally worth it.
Author and Publisher: Bigbrik Games
Latest Release Year: 2018
Number of maps: Currently 20
Get Square Here!