The biggest surprise for me was the https://hexbear.net count, an instance I hardly interact with.
| Community Count | Community Subscriber Count | |
|---|---|---|
| beehaw.org | 6 | 133450 |
| hexbear.net | 33 | 663204 |
| lemdro.id | 1 | 17052 |
| lemmy.blahaj.zone | 1 | 15907 |
| lemmy.dbzer0.com | 1 | 53006 |
| lemmy.ml | 14 | 356460 |
| lemmy.one | 1 | 16257 |
| lemmy.world | 39 | 851950 |
| lemmynsfw.com | 2 | 33586 |
| sh.itjust.works | 1 | 16006 |
| sopuli.xyz | 1 | 14093 |
The data this is based on comes from https://lemmyverse.net where you can just download a full json of the data they have (I excluded all communities marked as "suspicious")
EDIT: The data if you sort by active users last month:
| Community Count | Community Active Month Count | |
|---|---|---|
| awful.systems | 1 | 2616 |
| feddit.org | 2 | 7363 |
| feddit.uk | 2 | 5289 |
| hexbear.net | 1 | 2952 |
| lemdro.id | 1 | 2898 |
| lemm.ee | 3 | 8898 |
| lemmy.blahaj.zone | 1 | 11422 |
| lemmy.ca | 3 | 14910 |
| lemmy.dbzer0.com | 3 | 13752 |
| lemmy.ml | 10 | 54949 |
| lemmy.world | 57 | 338384 |
| lemmy.wtf | 1 | 3602 |
| lemmy.zip | 3 | 12020 |
| mander.xyz | 1 | 11469 |
| sh.itjust.works | 5 | 37365 |
| slrpnk.net | 3 | 10897 |
| sopuli.xyz | 2 | 10070 |
| ttrpg.network | 1 | 4107 |
Community Count:
Community Users:
They can be oriented to some type of content: For example, the many feddit.something are targetting people by countries or langages (.it, .uk, etc.). slrpnk.net is solarpunk oriented, mander.xyz science oriented. Litterature.cafe is books, reading and writing oriented.
And they can offer different moderation policies: People on lemmynsfw.com probably want to see NSFW content. lemmy.world has a policy against it. lemmy.dbzer0.com allow for open discussion about piracy that many instances forbid and so on.
It you don't see the difference in instances, it is probably that you are about fine on your local instance. But if one day, you hear about a community you can't access, maybe that is because it is blocked by lemmy.word and you could access it from another instance
If the dbzer0 instance allows piracy talk but I'm signed up to an instance that doesn't allow it, can I talk in their community or do I risk being banned from mine?
In other words, are my comments stored on their instance or on mine?
Your comments are stored on both. The "canonical" version would be on your home instance but every instance that is federated with your instance would get a copy of your comments. I think it's even possible to have your content removed from one instance but not another. One of my posts shows as removed in the mod log but isn't actually removed.
So by default your instance respect mod removals.
You can change that as a server admin, so comments would remain visible to other users on your instance.
I think your instance is authoritative for content of comments, but the community hosting instance is authoritative for which comments are approved (other instances respect such removals by default)
That's a good way of putting it. While my instance holds my canonical comments and the communiy's instance holds the canonical list of comments on a post, if the community's instance isn't federated with my instance (or the pair temporarily cannot communicate) then my comments won't show in the list.