Fiber vs Origami: What are the differences?
Developers describe Fiber as "An interactive UI Kit by Framer". Fiber UI Kit is the perfect starting place for your next project. Each element has been designed to work independently or as one seamless flow. It’s a full-fledged prototype with customizable components. On the other hand, Origami is detailed as "A free design prototyping toolkit for Quartz Composer". Origami is a free toolkit for Quartz Composer—created by the Facebook Design team—that makes interactive design prototyping easy and doesn’t require programming.
Fiber and Origami can be primarily classified as "Mobile Prototyping & Interaction Design" tools.
Origami is an open source tool with 3.35K GitHub stars and 467 GitHub forks. Here's a link to Origami's open source repository on GitHub.