[floatboth]

I think Alacritty was first. At least it became popular first.

[dijit]

Seems you are right, I always assumed alacritty was derived from the ideas in kitty (and hence the name being similar)

first commit in alacritty: Sun Feb 21 08:15:41 2016 -0800

first commit in kitty: Fri Oct 14 12:33:27 2016 +0530

[kristofferc]

The names are similar because they both do a wordplay on TTY (teletypewriter)