Esochess, customized chess (3/4 player, capablanca, two king) in C/WASM was posted to Show HN on 2021-01-08 at esochess.net. The domain now serves a parking page. The check recorded coming soon. The Internet Archive last captured it in 2021-03, about 2 months after launch — evidence it stopped, though a crawler losing interest is not proof.
Across the whole register, 23% of launches whose fate we could settle are gone.
How we know. Show HN and Product Hunt entries are judged by asking the domain whether it still answers: gone means it no longer resolves, refuses the connection, serves a parking page, or says plainly that it has shut down. An HTTP error is not counted as gone — a server that answers 404 is one somebody still pays for. Y Combinator entries use the status YC itself publishes, which is why only those can say acquired. Search the whole register.