FWIW, the OpenSSH devs believe it to be a potential security risk to adopt XDG:

> Adding additional configuration paths is confusing and potentially risky for .ssh as, quite unlike usual "desktop" apps, it grants system access and having its configuration smeared across several possible paths makes managing this more confusing and brittle.[1]

I think this is clearly true for something like ~/.ssh/authorized_keys; it is perhaps less true for ~/.ssh/config and or ~/.ssh/known_hosts which could go in XDG_CONFIG_HOME and XDG_DATA_HOME, but if part of the point of the XDG BDS is to reduce dotfiles in $HOME then it makes less sense to move some, but not all of those files.

1: https://marc.info/?l=openssh-unix-dev&m=170687803731931&w=2

I was curious about how old the original bug report was, and it appears to be 21 years old [0]!

[0] https://bugzilla.mozilla.org/show_bug.cgi?id=259356

I think there is probably a lot of work to do to fully pry the .mozilla folder apart. For a long time they've simply shipped everything in that folder and rolled with it. Making decisions on what is actually cache and what is user config vs "application data" is probably going to be harder than splitting the folder.

From that diff it looks to me that if ~/.mozilla exists OR if MOZ_LEGACY_HOME is set it uses ~/.mozilla, otherwise it uses the $XDG_CONFIG_HOME/.mozilla directory instead.

So no migration to the XDG directory, but also no throwing away your existing data either.

Looking at the full diff[0] it certainly looks like it's using ~/.cache (and has been for some time), but I cannot see anything about ~/.local/share, no.

[0] https://hg-edge.mozilla.org/integration/autoland/rev/8a6d6c0...

XDG is newer than firefox and hasn’t been widely adopted for the majority of its life.

Do you mean Firefox specifically?

The reason most software is not "XDG-compliant" is because most software predates the XDG basedir spec which only came into existence in 2021 (edit: oops, that's just version 0.8; version 0.6 was available in 2003)

It will be nice for software, as it updates, to support this standard which seems to be gaining adoption, and it will make users homedirs much cleaner. But it's most important for software to _keep working_, and have a migration path that doesn't lose the user's config or end up with two configs and not have a clear rule on which one it will use.