This post started as a response to @novacadian's question in a comment on an earlier post, but became wordy enough I figured it was probably best to put it right out here as an actual post.
The only free-as-in-beer rabbithole into the #Galactic-Milieu currently is still #Crossfire-RPG, whose metaserver still keeps neglecting to mention CrossCiv.Knotwork.Com and similarly neglects to mention the new "PTE Server" - #Play-to-Earn server - on Server1.Knotwork.Net.
The CrossCiv.Knotwork.com Crossfire-RPG server implements the "Galactic Diplomacy Planet".
Back when character race and profession was done on-map (which is still how the Java client does it) the maps sorted characters to keep fantasy characters out of the Science-Fiction milieu and even let Fighters choose a Nation (Civilisation) and go to an attempt at representing the #FreeCiv capital city of their Civilisation as Crossfire maps; with the advent of client-side race and profession choosing though (e.g. in the GTK clients) characters attempting to go to the #Galactic-Milieu get put in a version of the Schoolhouse that won't let them out, so they are stuck there studying and gaining experience at school until an admin manually examines the character to make sure it isn't a fantasy character and either transfers it to the real schoolhouse in the capital city of the diplomacy planet or to a starting-point in the fantasy milieu possibly coinciding with where the map-based character creation routes would have led them.
I think I pointed out in an earlier post that if we keep the "PTE server" we might not need to allow new users on the Galactic Diplomacy Planet (CrossCiv: Crossfire representation of a FreeCiv planet) anymore as we will be able to sort fantasy characters from non-fantasy characters at the "PTE Server" and they can do some kind of quest or something there to find passage on a starship or something to take them to the Galactic Diplomacy Planet.
Currently for example we are looking at the "Scorn Nobility" quest series for that, thinking maybe the only "planet that Scorn is on" folk who will get to go from there as Galactic Diplomats will be some high-ranking nobility types, and probably even though very Noble Scorn might only send humans who can pass for non-magickal humans (or maybe also gnomes who can pass as whatever one is allowed to label Ferengi in order not to violate any trademarks copyrights etc that might prevent calling them Ferengi?)
In line with Arthur C. Clarke's famous maxim that any sufficiently advanced technology is indistinguishable from magic it seems feasible that Scorn might be part of the "Hacker" civilisation in FreeCiv, so that to at least some extent we can maybe pretend a lot of what passes for magic(k) is really done via "Hacker technology", but even if that is the case it is anticipated that probably the Hackers will not want to "tip their hand" by sending actual magic-users, clerics, paladins and so on as Diplomats to the "mundane" civilisations.
Basically the advent of the "PTE Server" might be a harbinger of a closing window of time in which one can freely and/or easily get to the Galactic Diplomacy Planet, so it might be smart to grab an account there even if you are more interested in playing on the "PTE Server".
To clarify though, calling it "the PTE server" is not to be taken as implying that the Galactic Diplomacy Planet server is any less a "play to earn" server, the older server is however years more advanced along the road to being a sustainable economy; the PTE Server is so far almost un-modified from what Ubuntu 18.04 LTS installs and one can expect that if it is to be kept it will have to be nerfed in various ways. So far the only mod has been to close the per-player apartments system that by generating out of nothing massive residences for the players, that only they can even enter, not only undermines real-estate prices but also eliminates even the ability of canny thieves and assassins to get invited into someone's home to do something nasty in it...
-MarkM-