Carbon Design System from IBM: IBM's Open Source Design System and Component Library | Product Hunt
This is the 2nd launch from Carbon Design System from IBM. View more
Carbon Design System
IBM’s open-source design system for products and experiences
The Carbon Design System is IBM’s open-source design system for products and experiences. With the IBM Design Language as its foundation, the system consists of working code, design tools and resources, human interface guidelines, and more
I'm biased because I was at the literal beginning of IBM Design, but IBM Carbon is such an amazing design system to use and extend (both UX wise and aesthetically) for scientific data. Go take a look!