Chris Hogg wrote:

The Natural Philosopher wrote:

Blimey. I'm still on rel. 60!

Er...me too. Rel 60.9, and updated not too long ago. Are we talking
the same thing here TB = Thunderbird?

Yep ...

https://www.thunderbird.net/en-US/thunderbird/68.2.0/system-requirements/

Don't forget the version numbering on hunderbird only creeps up by a
minor number most times that firefox goes up by a major version, then
every few months TB "jumps" to catch up with the ESR releases.

e.g.

TB68.0 = FF68.0
TB68.1 = FF69.0
TB68.2 = FF70.0

so 52.x then 60.x and now 68.x are TB versions that align with the same
FF versions