Three.js

graphics

A JavaScript library that makes it easy to create and display 3D computer graphics in the browser using WebGL.

Pronunciation

Correct

three-jay-ess

/θriː dʒeɪ ɛs/

The number 'three' followed by the letters 'J' and 'S'. Creator Mr.doob and the official documentation spell it out this way.

Source: threejs.org(official spec)