Alibaba Ant Design Principles

Apple Human Interface Principles

Atlassian Brand Personality

Co-op Design Principles

Firefox Photon Design System Principles

Google Material Design Principles

:octocat:

GOV.uk Design Principles

Harmony Design System Voice & Tone Principles

IBM Carbon Design Principles

Lost My Name Design System Principles

Mailchimp Writing Goals and Principles

Nachos - Trello's Design System Principles

Seek Style Guide Principles

Living style guide for SEEK, powered by React, webpack, CSS Modules and Less.

Shopify Polaris Principles

U.S. Web Design Principles

Design Principles - a Guide

Good introduction and best practices.

Developing Asanas Design Principles

Inside article on how Asana developed their principles.

The Core Principles of UI Design

Short excerpt from Fundamental UI Design, an InVision e-course by Jane Portman.

Design Principles Guide to less shitty Feedback

Short introduction and practical guide on how to set design principles (with examples)

Built Environment Innovation Design

Lists professional design disciplines associated with built environment ventures and describes their roles (part of an open source project based learning challenge curricula).

Learn Design Principles

Learn how design principles can be applied from architecture to product design.

Design Principles FTW

"The biggest collection of Design Principles on the Internet."

principles.adactio.com

Huge list with various types of more traditional design principles.

Principles of User Interface Design

Long list with well explained principles by Joshua Porter

Principles of Product Design

Long list with well explained principles by Joshua Porter