Fediverse

You don't need to calculate the average number of active users. If you do, it will be wasted resources and you probably will miss a few dozen.

Simply request the instance's NodeInfo.

NodeInfo 2.1 (which Lemmy does implement) and I think 2.0 as well require implementors to provide correct user usage statistics. So you have total users and average active users per month/half year calculated on request.

This also means you can provide this service for other platforms that support NodeInfo.

Making a GET request to /.well-known/nodeinfo will give you the links to the instance's NodeInfo documents.

In fact, you can recursively begin from some random known instance, get a list of other instances it is federated with, get their NodeInfo and repeat the process. NodeInfo also provides the name of the software (check schema).

You can use that.

FEP: https://codeberg.org/fediverse/fep/src/branch/main/fep/0151/fep-0151.md

Schema: https://nodeinfo.diaspora.software/schema.html

Nowadays I just recommend Piefed.zip.

If someone wants a regional instance they usually figure it out by themselves, also the Piefed instance chooser can help and has a latency indicator: https://piefed.social/post/1337079

For the nationale behind, here's a list from a post on !fedibridge@lemmy.dbzer0.com that's a few months old https://lemmy.zip/c/fedibridge@lemmy.dbzer0.com?dataType=Post&pageCursor=P2d1f586&sort=NewComments

• Lemmy.world is too big
• sh.itjust.works names contains "shit", which can deter users
• lemmy.ca is Canadian-centric
• feddit.org, is German-centric, but technically English speaking too
• dbzer0 is focus centric
• programming.dev is topic-centric
• blahaj is queer-focused
• discuss.tchncs.de has a difficult name
• lemmy.sdf.org does not defederate anyone
• beehaw defederates LW and SJW
• infosec.pub is topic-centric
• aussie.zone is country-centric
• midwest.social is region-centric and admin can power trip at times (https://sopuli.xyz/post/20038037)