Your example is actually the only time I've ever seen this side-by-side-style login page with the form on the right. Mailchimp, Quickbooks, and Alliant CU, for example, use the same layout as OP. I'd guess that Rippling is really trying to push their marketing, which is why it's on the left. Source: almost 3 years ago

And, of course, you need a Mailchimp account. If you still haven’t had an account, create a new one here. - Source: dev.to / over 3 years ago

If you want something lightweight but at the expense of strict accuracy, I like the flexibility of Rellax. Source: almost 2 years ago

Relax (for parallax scrolling speed of elements). Source: over 2 years ago

Scroll-based interaction or animations have been popular for quite a while now. But most of the libraries I find either disable the browser scrollbar completely and implement their own scrolling based on css transforms (like locomotive-scoll) or dont touch the native browser scroll at all (like rellax or lax.js). Source: almost 3 years ago

I'm on mobile so I can't see the source but I'm pretty sure it's just parallax, you can just use something like https://dixonandmoe.com/rellax/ to make something very similar. Source: about 3 years ago