Elk, the Mastodon web client, has an excellent development setup with good documentation and solid leadership. There's lots of little fediverse startups. I've submitted some pull requests to Postmarks, a federated bookmark manager. It's very early stages and fun to be part of that!
What I’m looking for is lists or collections that I can create or the admin of the instance creates that combines common topics into a digest of subs. Then I just browse one digest on a topic rather than having to go through each separately.
Having Kbin and Lemmy instances use a common catalog of topic identifiers so they can be easily coalesced would be helpful, too.
I grew up in a very rural area of the southern U.S. back in the 80s. The internet wasn't quite a thing yet, so my window to the world outside my small town was our mailbox, located at Rural Route Box 464. I had pen pal letters, catalogs, magazines and comic books delivered in the mail and it was pure joy to run down the dusty road and check for something new every day.
The internet became my new window to the world, so it just seemed natural to use "Box464" as my address. Even got the domain!