A design system is a collection of documentation on principles and best practices, that helps guide a team to build digital products. They are often embodied in UI libraries and pattern libraries, but can extend to include guides on other areas such as 'Voice and Tone'.
*Projects marked as open source may not always be open to use. Always check the license of these projects before using them. Although 'design systems', 'ui libraries', and 'pattern libraries' are different things, they are often used interchangeably. This list contains all three.