Myst Online: Uru Shard Environments
Like D'mala, this would be the 'official' shard. Run by a team of Cyan approved admins (a rotating team?) The admins would eventually have the ability to open and close existing areas, add new content objects, make subtle changes to the world as the tech to do so advances. An official story reason would exist for why MOUL ages aren't available at this time. Both official and Fan run story could (and should) happen here, supported by the admin staff tools. Fan-made ages could be added to this shard after rigorous GoM review.
While the Admins could have the admin KI mods, only realistic mods would be available to the UserKI (light, /me, etc.)
GoM Test Shard-
Where the Guild of Maintainers can test out Stuff, like new ages, new toolsets, etc.
Public Test Shard-
The next step from the GoM Shard, the place people can come test out new fan-made ages & tools, with the caveat that Things Break, Here There Be Vault Wipes, etc.
Individually run Shards that allow the Admin and UserKI.
Ponder: Reasonable ways to make sure that a)people can have a playground, but b)the community doesn't diffuse between dozens of shards? Ideas: Lottery for pre-set number of shards? Neutral 3rd party run shard servers w/ rotating admin teams?
Ponder: Basic Code of Conduct for all Shards, simple things, like "Be excellent to each other", "Don't use unauthorised tools", "Thine Admin Has The Last Word", etc... plus the ability for a Playground shard to designate a rating "G, PG, R", so no one gets supprised, or has expectations about a place that might not exist.
People are already figuring out how to access MOUL and EoA content in earlier versions of Uru. We can assume that someone, somewhere is reverse engineering MOUL for a UU-type experience. And that at some point, those tools and builds will need tested where the fans can poke at them.
People are willing to pay for MORE. Will people pay for something even more fan-run, if a portion of the proceeds go to support a D'mala like shard: that is, a place where Cyan can participate. How could such a system be implemented? Kagi keys? Other user registration system?
The Ubiquitous Everybody just knows that there's underground shards running already. You can bet there would be with a relaunch of any UU sort of system. But the above shards would be the ones publicized, supported by Cyan and the GoM, and included in any new tools, builds and ages.