Alright I wanted to put more into that title, like "Tutorial" or "Comparison", but really I'm not experienced enough to provide that. What I am going to do is do my best to do those things, as I try to figure it out myself.
There literally seems to be no content out there on these topics. Only FAQ's, Discord's, and some lovely people who made videos playing them (just not ABOUT the randomizers themselves). Here is one such example, so you can get an idea.
Mashy's Video is of a multiworld, and I'll explain what that is and how it works in the post.
The idea is simple: randomize the items in either Ages or Seasons, and have fun trying to progress while finding items in random places. For example the randomizer I came across first to use myself (ages ago) was Karafruit, and I was playing it last night. I even got softlocked into an area, but luckily there is a randomizer menu that lets you warp to the starting town if you get stuck!
In this "seed" (what you call the modification for the randomizer, and each time is different) I found "Dimitri" instead of the sword. Who is an animal companion, that lets you traverse the water before you can swim. I also found the Roc's feather, an item you're not supposed to have until the 3rd dungeon. However because of this a large portion of the map opened up to me. I was still limited in a lot of ways though because I didn't have the Rod or the Sword. However in the area I was softlocked in, there was a portal to Subrosia, and since I had the feather I was able to go around a lot of that area. Even getting to the Subrosia Store, which happened to the have the Season of Summer (giving me the rod), and a big bomb bag (I had bought bombs in the main town store prior).
As you can see ^ this kind of thing truly changes the experience of playing the game. In this post I will explain the concepts of the Multiworld/Crossitems, share the links to the various versions of the randomizers, as well as any information I can to speed up the process for you.
Why would you want to do the Randomizer?
Many of us Zelda fans have played and played these games over and over. The challenge decreases with every playthrough. Not to mention the variety of games isn't very deep anymore, as Nintendo slowly drips them out. If you want a new experience, this is one way to do it!
A long time ago when I was still Spriting and creating 2D maps for video games I did a thing with Zelda maps. I actually merged the Oracle of ages and seasons maps into one. Now I took the liberty of placing things where it seemed the most fitting. However that was more of a creative expression, I bet there are ways to make it more logical for a combined game!
I also removed the gridlines, and if we were to create a map for a game it would need the grid.

The games have been out for over two decades, and most of us have played through them. I think I've only doing 90% of Ages ironically, so I could still replay that, but I still would love to play both at the same time.
What is multiworld?
It is the idea of combining both games in a real duality sort of way. You find an item in one game, and it could be for either game. You may start off Ages with a sword, but no Harp. Then you find the harp in the 3rd dungeon in Seasons, or somewhere else. You go back and forth to
What is CrossItem?
A pretty simple tweak that adds a lot of replay value. It allows for ages items to be in seasons, as well as seasons items to be in ages.
Without playing full on multiworld, which is harder to set up and play, then this is the next best thing. Ideally doing both though!
Various versions of the Randomizer
Now while there are a handful here, and that may be overwhelming. They are more so just different versions by different people that wanted to add different things.
In the end it comes down to personal preference, what you're wanting to try, and just experimenting!

Ironically though I would probably suggest the latter two, as they are more feature rich. However perhaps the implementation of the earlier ones could be more stable? Let's go through each of them.

jangler - From what I gather the "original" randomizer

Manual - https://jangle.dev/oracles-randomizer/manual.html#multiworld
Web UI Version - https://cemulate.github.io/oracles-randomizer-web/

Stewmat - https://oosarando.zeldahacking.net/
One of the main forks of the original.
Web UI to make the randomizer
https://github.com/Stewmath/oracles-randomizer-ng
https://www.youtube.com/@Stewmat
vinheim3 - https://github.com/vinheim3/oracles-randomizer
I can't tell what information to share here, it just seems like another fork, with some additions. I think perhaps the dev might have moved over to other projects to help there? I could be wrong.
Karafruit (The one I used)
Arguably one of the simplest ways to do it, which is probably why I went with it. What I've played so far has worked out well, and starting out with Dimitri instead of a sword has been super interesting. Though for you it could be different! I would suggest using the cross items too.

https://oracles-dev.gwaa.kiwi/generate
Archipelago
From what I can tell this is the main one in development nowadays. The rest don't SEEM to be going still?
Archipelago however requires Bizhawk emulator, along with what I assume is a tool called archipelago to make the rom in the first place. Probably similar to the interfaces you saw in the screenshots above.
While it might seem more complicated, and it technically is for the advanced features. If you want the fullest experience, this would be the way to go. I.e. multiworld AND crossitems.


If you want to play on mGBA instead of Bizhawk here is a script to help you. You still need to use a server for the multiworld/tracking, but at least you can use a different emulator. https://gist.github.com/Zunawe/d41677500b08694c9985f67f41896cc5
How do you decide which to use?
I think if you want the most features you can pick between the Karafruit and Archipelago versions. The former is more standalone, and you can play on any emulator. However the latter needs bizhawk to mostly work, and while it too can work on any emulator if you just use the randomizer portion. The main reason why you would use the latter IS for the majority of other features. I.e. multiworld, and jumping between games.
The version I had ended up on, and I'm not sure if I had compared before as again I created the randomizer for myself a long time ago haha; Was the Karafruit version. That seemed to be a very easy to follow method, and while some of the other versions are easy too. They are either not continued in development, or they lack crossitems or multiworld.
Thus choosing one of these two are what I would suggest. Also do note that since the Archipelago version is still being worked on, if you are reading this down the line. Then perhaps that version will be even more feature rich, and perhaps even easier to use at that point. Time will tell.
Conclusion and Other Resources
My first encounter with a multiworld was actually a Tale of Two Wastelands with Fallout 3 and Fallout New Vegas. Then down the line I saw Pokemon Emerald and FireRed multiworld.
The modding community is astounding, and thank you all for the work you are doing!
Bad news:
I think my first randomizer is hardlocked. I had progressed as much as I possibly could. I even prompted Claude to be my speedrunner advice hype man, and it just came up with nothing I haven't already tried. That sucks.

Wasn't sure who this was under, and where it should go. But it was a link so I include it I guess.
Lunar IPS - If you don't use a web UI you might need an IPS Patcher
https://www.romhacking.net/utilities/240/
Romhacking
While not the same as what these randomizers are doing per se, the games are old enough that people could hack them like they do with Pokemon games. Here are the links to the pages that people would normally upload such hacks. There aren't very many at all at the time of this writing.
SEASONS https://www.romhacking.net/games/791/
AGES https://www.romhacking.net/games/1421/


Including Oracle of Hours
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AP world https://github.com/SenPierre/ArchipelagoOoA/releases/tag/ooa
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"Crossworld" another project I came across I think from one of the aforementioned Devs, and now while it could be the python interpreter I used. I ended up getting this result...
