Question related to an article from your blog section

Hello,

In this article :

https://premium.wpmudev.org/blog/adaptive-image-optimization-for-responsive-wordpress-themes/

The author said that "New Nine Adaptive Images" is doing the job. But when i clicked on the link, it leads to a 404.

I tried 2 other plugins for adaptive images and none worked. Did adaptive images became a feature of Wordpress? Because it resizes the image without any plugin.

Regards