People have suggested that FO should support/endorse PolyMC (e.g. #296) because of its additional features and Modrinth support and ATLauncher because of Modrinth support. Both should also support Quilt (#257).

However, here's my current stance on this subject:

• MultiMC forks - to my knowledge they are still just forks, with all the pros and cons of MultiMC, so at the moment there doesn't seem to be a substantial reason to recommend one over another and as with any forks, they may not be as up-to-date with feature and security updates as they should.. Maybe if one of those make the modpack updating easier, it would give a better reason to consider.
  Edit: PolyMC will be supported due to high interest and planned modpack updater
  Edit 2: PolyMC will not be considered and instead its fork, Prism Launcher is now supported
• ATLauncher - it's good that it seems progressive with Modrinth and Quilt development, but the last time I checked it still has bad UX from FO standpoint because it prefers its own modpack repo (aka you can't just search "Fabulously Optimized" and click install, it needs more clicks).
  Edit: this issue no longer exists, but it still needs some UX improvements before I'll consider.
• Modrinth launcher (WIP, #63) - I will endorse it when it gets released and FO becomes stable (sustainable) in Modrinth.
• Others - know any?

Edit: See #297 (comment) for current plan.

Thanks for the reply. I checked it out again and reported some usability problems but yeah, the UX needs more work overall.

MultiMC forks - to my knowledge they are still just forks, with all the pros and cons of MultiMC, so at the moment there doesn't seem to be a substantial reason to recommend one over another and as with any forks, they may not be as up-to-date with feature and security updates as they should.. Maybe if one of those make the modpack updating easier, it would give a better reason to consider.

PolyMC is a lot more updated than MultiMC, take a look at the commit history

PolyMC is a lot more updated than MultiMC, take a look at the commit history

Fair, but I'm still waiting to see more differences that would improve the UX in some way. Downloading mods for example is not a good reason, because as far as I see, there is no update feature for those either.

PolyMC is a lot more updated than MultiMC, take a look at the commit history

1. Most likely reason is the main developer currently away from most dev stuff. And as Madis0 said, it's still fundamentally the same launcher, installing and updating modpacks don't change either.

2. PolyMC isn't old enough to shake off all the trolls, as they still post meme comments on MultiMC PRs. I feel like the launcher needs to mature a bit.

1. How is he away from most dev stuff since PolyMC exists
2. That person is not on the PolyMC dev team

1. How is he away from most dev stuff since PolyMC exists

this makes absolutely no sense, but maybe I should clarify: Peterix stated that he was currently away from most dev stuff in the MultiMC discord. I don't understand how that has anything to do with PolyMC's existence

There's already Some preliminary work is in progress

PolyMC/PolyMC#426

As far as I see, there is no update feature for those either.

A mod/modpack upgrader in on their milestone for the next release, speaking of PolyMC (PolyMC/PolyMC#65 & PolyMC/PolyMC#274)

ATLauncher - it's good that it seems progressive with Modrinth and Quilt development, but the last time I checked it still has bad UX from FO standpoint because it prefers its own modpack repo (aka you can't just search "Fabulously Optimized" and click install, it needs more clicks).

Just to add to that, it's much more streamlined now. All modpack platforms have the same flow now. Previously it was 100% biased towards our own platforms packs, but since majority of the packs on our platform now are released on multiple platforms, and that is definitely the norm now, the UX was updated (see https://cdn.atlcdn.net/java_31xRIU4o4i.png for more of an idea of what it looks like now) to be much easier now.

I'm guessing you may have last looked around the time where it was just installing packs through a button, rather than any sort of real UI.

Overall I'm not really happy with the UX of the launcher overall, but it's slowly being built up and refined to be much better over time, section by section, piece by piece :)

I don't think modpack updating will get in 1.4.0, probably will be delayed, but for sure 1.4.0 will have a mod updater!

Bringing this issue back to life by saying that PolyMC plans to give the ability to auto-upgrade modapcks and mods on version 1.4.0! Currently, they are working on version 1.3.0, which also brings some very useful features.

This is the current plan for supporting various launchers in FO. Mod source platforms vs launchers.

• The graph does not indicate all capabilities of the launchers, but rather the ones I would like to recommend and support
• All platforms also support individual JARs to some extent, but this should be used minimally, so it is not indicated here
• Some mentioned launchers don't exist yet
• Support start depends on various aspects, including UX improvements and CF API situation settling #169

For example, PolyMC would prefer Modrinth because:

• CF direct download would not increase download count and would have partial integrity
• CF prepacked format would give no updatability
• Packwiz would be too rigid by forcing updates, harder to disable mods and no increased download counts
• Modrinth would give a way to update the modpack seamlessly while also increasing pack's download count

ManyMC is now based on PolyMC, as of version 0.1.0. A PolyMC release with official M1 support is planned soon (via).

Prism Launcher (a fork of PolyMC) is now supported. PolyMC itself will not be.

A good resource of launchers to test: https://github.com/modrinth/awesome#launchers

Not actually a good idea to add new launchers to support just for the sake of it - if something new and popular will come, I'll consider it anyway. So, for any new launchers - create a new separate meta issue.