ZDoom

My computer is running on Windows XP, and I'm using ZDoom 2.8.1 because GZDoom doesn't support XP. I've been having some trouble finding mods that will actually work with the version I've got, so far only Brutal Doom V.21 has worked, others I've tried have come up with error messages, and since it's ZDoom, it can't run GZDoom mods like Halo: Doom Evolved. Are there any good mods other than that that would work? Specifically any good Halo themed ones?

You will have a hard time getting mods to work on this old version. It is 7 years old by now. Most mods have moved on and embraced ZScript later.
Depending on your graphics card you should still be able to run GZDoom 3.4 or 3.5 which would mean a lot more compatible mods.

But in the end you are running on borrowed time here. XP has been off support for what? - 9 years by now? - and increasingly more software will leave XP behind eventually.
Is there any reason you cannot upgrade to something that doesn't force you to compromise this badly?

After some investigation i've found that the last GZDoom version supporting XP is 4.1.2b: https://zdoom.org/files/gzdoom/bin/gzdo ... 4-1-2b.zip

Then LZDoom 3.8.7c also runs on XP with a patch here: https://github.com/drfrag666/gzdoom/releases/tag/3.87c

My mod OldBlood is ZDoom 2.8.1 compatible.

drfrag wrote:
> After some investigation i've found that the last GZDoom version supporting
> XP is 4.1.2b: https://zdoom.org/files/gzdoom/bin/gzdo ... 4-1-2b.zip
>
> Then LZDoom 3.8.7c also runs on XP with a patch here:
> https://github.com/drfrag666/gzdoom/releases/tag/3.87c

GZDoom claims that it needs at least OpenGL 3.3 to run, and my computer doesn't have that. Everything I've found on the web says that you also can't just install a newer version, it's a part of the PC's drivers.

That'd leave you with GZDoom 3.3 or 3.4. It was either before or after 3.4 that GL 2.x support was dropped.

LZDoom is based on GZDoom 3.3.2 with a lot of later stuff added.

Would you not be better off with something like Woof? There are some pretty impressive mods and wads using MBF21 and UMAPINFO.

Mods, not maps!

Woof cannot run DECORATE based gameplay mods.

Alright, I'll try GZDoom 3.3 and see if that works.

Wait... the old version of GZ doom can run in XP?

3.3 should be fine. XP compiler support was dropped a bit later.

Try Graf's suggested version as that will open a lot more options, though you may have to look for older versions of some mods. Failing that, DoomRL Arsenal is (ostensibly) one that still supports ZDoom and it's a classic, so also check its monster mod and LegenDoom (Lite) which may also work. There's also an older download for Colourful Hell that supposedly works. With GZDoom try Project MSX, it's not Halo but does borrow a few things, and check through the Cacoward mods from 2018 and earlier.
EDIT: Wrath of Cronos MAY work on ZDoom as well, you'll have to check but it at least should work on the older GZDoom.