Doom 2 version is mini episode with decorate things recommended to play through (That's not the normal map02 Underhalls). Doom 1 version I really felt the need to see all the vanilla format maps working in vanilla doom.exe and aligned some more of the original texturing better. Both have some different ZDoom maps and have something to offer that other doesn't, whether as secret maps in Doom 2 or additional episodes in Doom 1. ClassicT.wad is the best set of textures to use though EntHangP has more evenly animated version of brown slime flats you may want to grab. Only the Doom 2 version has additional sprites while both versions have different decorate things to offer.   Only D1 version has Eternity defs.   Both have decorate things not actually used in any of the maps.   Editors can use whatever resources they like.  Just make sure you credit other people whose textures I used from the Post-Your-Textures topic.   New universal Ultimate Doom version (released around midnight April 25th, 2020) Works with no prep with doom.exe though you may want to apply D1EntHng.deh for E4M1 and map names. Doom Classic 2019 and many source ports specially supported. Doom 1 missions replaced sporadically with their versions from EntHangP but all made doom.exe compat. Episodes 1&2 Secret missions replaced and added. Episode 5 for Odamex/ZDaemon (2 Hexen format maps)
Episode 6 for Eternity Engine (2 UDMF maps)
Episode 7 for Zandronum/LZDoom/GZDoom/newer ZDoom (4 UDMF maps) Some different maps not in EntHangP.wad.   Main mini episode for Doom 2 with any ZDoom based port supporting UDMF and Decorate (released around midnight March 14, 2020): Currently untested with K8vavoom (supports UDMF and Decorate). See further down for just texture wad and a single map vanilla wad.   Map01: Entry-Hangar described below (UDMF) Following are vanilla format with some decorate things: Map02: Better v1.666 version with early version and BFG edition stuff Map03: E2M3 Refinery with SNES,PSX, & Alpha stuff. Map04&05 skipped past with mapinfo Map06: E1M6 based on much different Alpha version mixed with other Alpha and Ultimate Doom versions + some PSX things Map07: E2M7 Spawning Vats with Alpha and PSX stuff. Map08: (3DO extramap) Altar of Extraction including many early and Alpha map pieces with a grand finale fully living up to its name. (End of mini episode) Secret exits in four of those.   Music entries are named so you can override them with IDKFAv2.wad whether it's Doom 1 or 2. I have not tried this with Brutal Doom though. The Doom 1 version is set up to play appropriate tracks of Bobby Prince's Doom Music CD if you have it in, if whatever ZDoom port supports that feature.   PSX secret exit added to Map16. Alpha things emulation plus more of them implemented and many unused things added. A full list of things with DoomEd and Spawn ID #'s is at the bottom of decorate, but it'll spoil surprises. They were carefully chosen to avoid any conflict with Skulltag actors or anything I saw in zandronum.pk3.   Every map contains at least one secret.   Not all secrets count as secret (because they're super secret). One of the secret bonus maps requires either mlook or jumping. Another bonus map requires mlook to get its only secret. Bonus maps are a variety of formats.
  Remember to try AltFire with any new weapon or the BFG.   Due to generous ammo placement of the original maps, you may want to try pistol starts.   By map06 I had all ammo maxed on UV despite new surprises.  Or go Nightmare!  Or just try -fast monsters if Nightmare is too much.   ClassicT.wad for anything.   (For vanilla Doom2.exe, delete Nukage1-3, Blood1-3, OR add all flats) EHvanill.wad included.  (Same as map41 in EntHangP.wad except starts 5-8 changed to multi-only bodies/blood) 4/29/20 Properly tested in vanilla doom2.exe Deleting decorate things and coop starts 5-8 in any other vanilla format map should make them doom2.exe compat but you'll be missing out.   EDIT: D1EntHng.wad coming soon, universally compatible with doom.exe,Doom Classic 2019, and various ports.   Some vanilla maps needed work to be truly doom.exe compat and Odamex/ZDaemon intended Entry-Hangar now has PSX color lighting using an ACS script to set it all.   ClassicT.wad lets you play Doom 1 maps in Doom 2 + all the textues used by early Doom 2 maps that were cut from the final game, more that were cut from earlier texture listings, more unused ones, many Alpha version textures edited to work better with the regular Doom, and much more.   If I used your work, you should be credited, but reading texture credits before completing the episode may contain spoilers.   Several versions of E1M1 and MAP01 mixed together...
                          Combined rather seemlessly and staying true to
                          offical version parts.  It is composed of...
            First X-box version E1M1
            + Early July '94 version of Map01 from d2temp-cleansed.wad
            + some of v1.9 Map01
            + some of Plutonia map32 (thing placement toned down)
            + thing placement from PSXDoom Hangar (Doom 1 Map01)             + PSX colored lighting and light levels averaged between PSX and original
            + one stimpack placement from v1.1 E1M1
                        + minimal architecture to facilitate combination
            and minimal things in new sectors.   Other versions to warp to: Map40: Odamex/ZDaemon compat Hexen format (colormaps in unswimmable liquids) Map41: Vanilla format but has coop starts 5-8. Map42: Similar to map01 but PSX light levels Map43: Similar to map01 but original light levels. Map40 and 41 don't have the PSX color lighting.   Colormaps look better in software mode while PSX color lighting looks better in hardware. Any other???   Anyone is welcome to come up with some Eternity definitions or EDGE DDF version of my decorate for another edition, but two Hexen format secret maps would have to be converted to UDMF (which I would gladly do).   (Edit: one of those Hexen format maps whether in that format or UDMF is only workable in Zandronum or newer ZDooms.   The ThrustThing linedef/ACS special is too limited in Eternity and older ZDooms.   I tried.)   New screenshots, not spoiling any of the best stuff.   New vanilla version screens taken with -devparm.   Automap not fully revealing everything.   Older version but newer than previous release used for these videos:   Old crap version:   Zandronum makes multiplayer things appear in single player deathmatch mode if you want to try that but turn monsters on.   I hereby demand some version of this map is stuffed somewhere into every deathmatch level pack for every game from now on.     If you want a chopped up, rearranged mix of E1M1+Map01, check out map01 of dwango7.wad, Best of Both Worlds by MrBlonde It's also map02 of dwango9.wad.  Although looking at the automap, it's not that ambitious and mostly substitutes two map01 rooms for two of E1M1, and a version of E1M1 before Ultimate DooM was used.   It's nice looking though. It's also map16 in Doomkid's Jumbo Dwango.   Here's a really ambitious merger of E1 Missions 1,2,3,4,&5, but not Doom 2 map01.   Learned of this recently while working on my project: Pretty awesome and trippy and did different maps than I did, going in way different directions, except for Spawning Vats, but did a way different version based on the PSX version expanded further.  I actually haven't finished playing through it yet as it's very long and some parts are a bit confusing/frustrating.   I should soon though.   A very worthwhile experience and adventure.   OLD boring screenshots without spoiling too much from the first version months ago.