Core-js is available on npm[^1^][1]. It is not backed by a company, so the future of the project depends on its users. The project is raising funds through Open Collective, Patreon, Boosty, Bitcoin, and Alipay[^1^][1].
There are several ways to use core-js. You can load the entire library or only the required features. You can also use it without global namespace pollution by importing individual features from 'core-js-pure/actual'[^1^][1].
Core-js is integrated with Babel and is the base for polyfilling-related Babel features[^2^][4].