I saw this item in a thread on BitcoinTalk
Apparently, bitnodes.io was run by someone named Andy.
Unclear whether they are going to try to get it back up or have decided to stop maintaining the project.
@lopp is predicting that lots of other node-count services will go down because they were just getting data from bitnodes.
Luke Dashjr's node count monitor is still live:
https://luke.dashjr.org/programs/bitcoin/files/charts/software.html
https://luke.dashjr.org/programs/bitcoin/files/charts/historical.html
The BitMex node is still publishing a node count:
Lopp has a page where he lists a number of various bitcoin node count sites:
https://www.lopp.net/bitcoin-information/statistics-metrics.html
All good things must come to an end, it's the circle of life.
I'd rephrase it: All good things must come to stackerNews
Bitnodes has been the default reachable-node count reference for years. If it does go dark, Luke's node crawler and Coin Dance still track some of this, but nothing with the same clean API. Worth someone forking the open source code and keeping it alive-the data matters for understanding network health.
Here's a handy node monitor I didn't know about:
https://www.dsn.kastel.kit.edu/bitcoin/index.html
Between this year and next year a lot of projects will shut down
https://twiiit.com/lopp/status/2052725200421286301