I suggest doing a larger number of minor versions so as to have a fast release cycle. KMOD 4.0 should have the basics on which 4.1 and later can build.

To determine the feature list of 4.0, we need to first compile a full list of all work that is 100% implemented and ready to go.

Just edit the category posts below to add everything you know is done and available. Also feel free to rearrange/rename the category posts.

RPG elements (code and artwork)

Coded
Character stats (Strength, dexterity, etc)
Experience and leveling

Monsters (code and artwork)

Features
Coded
Advanced AI:

Navigation (Optional, requires placing navigation objects on map, otherwise ignored)
Ability to perform scripted orders: patrolling, following, attacking, pressing buttons
More ways to customize behavior, like what makes monster alerted (via map scripts)
Ability to perform tactical moves, like evasion (only basic implementation ATM)
Teams

Capability to make monsters serving as "saddle horses" for a player or other monsters (probably working, but wasn't tested much)
Monsters dropping sliver and gold bars (that is easily customized)

New monsters
Coded
fully or nearly fully implemented (need balancing though)
(detailed info can be seen here: viewtopic.php?f=20&t=2072)

Ettin Slinger
Ettin Flechetter
Ettin Commander
Spectral Centaur
Flame Centaur
Dark Cardinal
Dark Advisor
Ghost
Magma Stalker
Lava Dweller
Afrit Leader
Afrit Martyr
Chilling Myst
Poisonous Myst

Artwork
???

Weapons/spells (code and artwork)

Coded
New weapon inventory (weapon belt)
Spell inventory

Miscellaneous

Coded
Spells that act as stand-alone actors in game, which make it possible to use same spell both as player's and monster's weapon. Special spell types that are layed on player and monsters and perform any sort of custom alterations.
Travel map
Scriptable conversations

Once the category lists above are filled, we can discuss in further posts which ones should be part of 4.0. Crimson also asked about maps, I'd say with the rapid release cycle we could always just do a little bit of stuff on a map here or there as fancy strikes us and include it in the next release.

Depending on which KRPG features should be toggled off, and which KMOD intrinsic features that are not needed for SE should be added to KRPG, we may either use same code branch or create a new one for KMOD.
Some of the KRPG parts are optional (like monster navigation) and simply not processed in abscence of required resources/map objects.

Probably no forking needed, as no features work differently, they are simply either active or not. Given that KRPG is based on KA code, I'd guess it has all multiplayer stuff in it as well, meaning there is nothing KMOD 4 needs that KRPG wouldn't have (cooperative mode is a must for KMOD 4, whereas KRPG has no multiplayer).

No, and no, it hasn't. I think it was based on Vavoom Hexen. Ofcourse, some things were copied, but not new Bot AI and not KA inventory and other KA objects.

Hm then a fork would be needed for multiplayer in KMOD4?

Since multiplayer may be disabled by simply hiding "multiplayer" option in main menu, possibly this won't be a reason to use different copy of the code.
But... well, this depends on other differences. Perhaps making separate project will be more safe anyway.

How about 4.0 is single player only, and we work on the RPG, UI and monster stuff first? 4.5 would be the one introducing cooperative (further multiplayer modes are not needed anyway, that's what KA is for), and any releases below that would be still single player only, and would be essentially still the KRPG version?

As a theoretical example:

- 4.0, introducing basic RPG features, new monsters and improved monster AI
- 4.1, adding new weapon and spell UIs, travel map, NPCs with conversations
- 4.3, adding shopping (buy and sell) and some other stuff
- 4.5, adding cooperative multiplayer support
- 4.6, adding cooperative mode with bots

With a roadmap along these lines, it would still be the KRPG codebase up to and including 4.3 and then at that point it would be forked, and the fork called KMOD4 or whatever and adding in cooperative stuff.

That's okay; just one question: will KMOD4 use same weapon system as SE? Different weapons (from both games) can "live" in the same code, but weapons inventory handling in KRPG is now much different from original Hexen.

I guess that means the new weapon UI (the deadline for which depends pretty much on Firebrand's time) has to be finalized for 4.0 instead of for 4.1, or can the unfinished new system co-exist with the legacy weapons? Or maybe we could use the KA weapon system for the interim?

Not sure what you mean when saying "KA weapon system". KA used same system as original Hexen.

To elaborate, there are 2 weapon systems (they differ both UI-wise and code-wise):
1. Original Hexen system, like any else game of that kind: a number of slots bound to certain keys (numbers by default), each slot may held a number of weapons, which types are, in general, not restricted (i.e. hypothetically there may be any types on same key). All weapons are freely chosen by pressing number keys.
2. New KRPG weapon system: a number of categories bound to certain keys (e.g. numbers), each category helds a number of weapons, restricted by type. Player sets up an active weapon for each category in special arsenal menu and then can only toggle between those pre-selected weapons (he needs to reopen arsenal menu to make different weapon set).

Codewise KRPG system is fully implemented; UI-wise it is implemented as a plain text menu (AFAIK).
And yes, it is absolutely possible to use legacy weapons with it (just needs little changes in code). In fact all original weapons are still in KRPG.