Source: I know Wes and talked to him about it a number of times online and IRL (he was also pretty good pals with Kevin Lawler -we all lived in the Bay Area at

Source: I know Wes and talked to him about it a number of times online and IRL (he was also pretty good pals with Kevin Lawler -we all lived in the Bay Area at the same time: none of us do atm, which is anecdata for the perpetual "fleeing bay area" thread). I originally got to know him as I was thinking of participating in the startup he had done that eventually got bought by cloudflare as he was explicitly hiring J dudes. Anyway, ask him; he'll tell you! data.tables in R has some strong resemblances to J notation as well; might be one of those inevitable things (Greenspun's 10th applied to array programming/APL), but I never talked to the author.