D3 started out as an academic project and Vega/Vega-Lite come from the same lab. Also, while Vega does not generate D3 code (Vega is a declarative visualization

D3 started out as an academic project and Vega/Vega-Lite come from the same lab. Also, while Vega does not generate D3 code (Vega is a declarative visualization language and reactive runtime), it uses the D3 libraries internally and is heavily inspired by some of the core principles (e.g. data join).