There was indeed something called “BIND 10”. There is no BIND 10.
1. <https://www.joelonsoftware.com/2000/04/06/things-you-should-...>
ISC was heavily invested in BIND 10, to the point I even got a sticker. That combined with a 1.x release are what make a software project production ready.
I'm sure everyone remembers history differently, but had ISC not gone into cost cutting mode Shane wouldn't have been laid off and we'd all be arguing over what BIND 10 alternative is best. :)
It existed, and even still exists, since people still buy and drive it. But nobody would use that “BIND 10” release today.
This is because software is different from cars, in that you need to use an up-to-date version. You therefore depend on there being a current development branch.
In this way, software is not like cars; it’s more like something like a TV channel or a magazine subscription. If a magazine stops publishing issues, or a TV channel stops transmitting, you wouldn’t say “Omni Magazine is…” or “The Festival TV channel is…”, even though video recordings and magazine issues still exist.
Regarding Whois clients specifically, it seems that Debian maintains its own Whois client: <https://github.com/rfc1036/whois> This is something which Debian usually does not do, and when it happens, it usually means that there is no updated maintained version available, but the software is too important to remove.
You can download BIND 10 release 1.2 here: https://downloads.isc.org/isc/bind10/latest/