Arh I see what you are asking for now. Yes, DevilutionX will support widescreen and different resolutions, but we have to clean up some more code before it lands (progress is good though). The way we do upscale should already be more robust then what GoG does with wrappers. We are also going to feature some of the graphics enhancements that you have seen in Belzebub; true transparency, full-color lighting and hopefully per pixel lighting instead of per tile.

The screenshots on the page are more of a proof of concept. Raw Devilution won't support anything more than what the 2001 release of Diablo did and will have the same bugs etc. it's sort of an archeology project :)

DevilutionX will probably get most of the improvements you mention here, the developer of Infinity is currently working on Devilution, once the clean up is done and general QOL features implemented in DevilutionX he will be developing Infernity2 on top of it.

P.s. PrintScreen is unimplemented at the moment (the console should actually say that is why it exited if you keep it open). This is a know missing feature (see release notes) and should be solved by the next release.

I just want something that works with the GOG release and gives alt-highlights, single player difficulty selection and literally nothing else =[

there are now two mods that adds this;
https://discordapp.com/invite/qS2GNT9
or
https://github.com/Manuel-K/devilutionX-QOL-patches

Looks like those are for Linux/Unix. I've no idea how to use the .patch files with Windows.

A few of those are too long for me to be sure, but none of them look Linux specific. You should be able to use them to patch the source on any platform, then build the result. If you're not comfortable building DevilutionX yourself and prefer to run a build created by someone else, then those patch files won't help you, regardless of platform. Even Linux users would need to recompile DevilutionX after applying the patches.

Oh, so they are source files. Well I've never compiled an application from source code before, so I've no idea what I'd need to do.

Technically, they're a machine-readable description of how to change the DevilutionX source files from what the DevilutionX authors post into source files that have the specified change (different monster rendering, etc.). They aren't really source files on their own, in that if those patch files were all you had at hand, you couldn't build a working game out of them. You would need the DevilutionX sources too. None of that helps with your original problem though.

DevilutionX's README.md has some instructions for building from source, but if this is your first time, I suggest you either be prepared to sink some time into it or to ask someone for help. The README has enough detail that someone who has done these before could figure it out pretty easily, but if you're starting with no experience and no build environment, you'll be a bit lost. (For starters, it assumes that you already have Visual Studio installed, and doesn't tell you where to get it. Visual Studio isn't part of a standard Windows install, so you need to download it from Microsoft and install it before you begin. There may be other assumed dependencies. I didn't check.)

I was just informed that the QOL patches have now been compiled into a Windows executable. Here's the link.

https://github.com/Manuel-K/devilutionX-QOL-patches/releases

The left mouse button auto-clicker (just hold it down to repeatedly attack) and the item highlighting when pressing Alt, are great additions to DevilutionX.

So I downloaded this and put it in my Diablo directory, when I run the game the menus work fine but in town I get 20 fps and my mouse isn't responsive. Any ideas?

I figured out the issue is the autoclicker. I would love if some nice person would recompile the game with all the QoL patches besides the autoclicker. I don't understand how anyone can play the game with it turned on. Its godawful and keeps locking up my mouse and making my computer beep at me.

Is there a link that doesn't require me to sign up for Discord? Alternatively, is it even worth looking at/is it better than the second set of patches you linked to?

Diablo was hardcoded to run at 20fps. DeviltuionX 0.6.0 will remove this limitation though.

Maybe here https://www.tapatalk.com/groups/sergi4ua/

I tried to make a new account on the github, but it was flagged so my post is not visible there.

I was wondering if it it could be possible to add an option that would allow drop of multiplayer only spell books/scrolls (heal other, resurrection) in singleplayer in devilutionX.
I know those would not have any use, but for roleplay/completion sake I think it could make an interesting addition.

everything is possible

I just discovered this Source Port, and i saw that they were applying per pixel lighting. Is this avaiable already?