[orhmeh09]

Oh, I know that, I use it daily and I’ve read some of its source code. I’m just astonished that the best-performing data frame library in the world is developed in R and it outperforms engines written with million/billion dollar companies behind it.

[hugh-avherald]

data.table is written primarily in C. But R happens to have a very good package system and a very good interface to C code.

And Matt Dowle has bled for that C code.

[dm319]

I feel like some of it is to do with the way R's generics work - being lisp-based and making use of promises. It allows for nice syntax / code while interfacing the C backend.