It should be noted that the speaker is one of the lead developers at Naughty Dog, likely one of the greatest game studios of all time. Definitely recommend a watch.
Interesting to hear how they replaced GOAL in their toolchain. The people I've met who used GOAL in the past talked at length about how much they miss it.
Parent is referring to GOAL/GOOL [1], Lisps that were developed internally at Naughty Dog for game scripting (the first iteration for the Crash Bandicoot series, the second on for the Jak & Daxter era. It is said that these were very powerful systems that could compile to some very mean PS1/PS2 assembly. If you read about how they had to optimize Crash Bandicoot to be able to give that "wow"-factor at their first E3, blazing past all other PS1 games and setting a new standard, you'll know what I mean.
There's a very interesting blog series about it [2].