Design knowledge — source index
Purpose: Master list of external knowledge bases and references. Our topic docs distill principles; this index is where to go deeper.
Harvest / review: 2026-05 — Verify links annually. Do not reproduce paywalled content.
Tier key: T1 = free, authoritative, link-stable · T2 = free summaries + paid depth · T3 = open reference implementations
Accessibility (T1)
| Source |
URL |
Use for |
| WCAG 2.2 Quickref |
https://www.w3.org/WAI/WCAG22/quickref/ |
Filterable success criteria |
| W3C WAI — WCAG overview |
https://www.w3.org/WAI/standards-guidelines/wcag/ |
POUR, policy context |
| Understanding WCAG 2.2 |
https://www.w3.org/WAI/WCAG22/Understanding/intro |
Non-normative explanations |
| The A11y Project |
https://www.a11yproject.com/ |
Practical how-tos |
UX research & design thinking (T1)
| Source |
URL |
Use for |
| NN/g — 10 Usability Heuristics |
https://www.nngroup.com/articles/ten-usability-heuristics/ |
Heuristic evaluation (free posters) |
| NN/g — Conduct heuristic evaluation |
https://www.nngroup.com/articles/how-to-conduct-a-heuristic-evaluation/ |
Audit workbook |
| Laws of UX |
https://lawsofux.com/ |
Psychology principles for UI |
| Stanford d.school — Design Thinking Bootleg |
https://dschool.stanford.edu/tools/design-thinking-bootleg |
Methods cards (free PDF) |
| IDEO — Design thinking |
https://designthinking.ideo.com/ |
Desirable / viable / feasible framing |
| IxDF Literature |
https://ixdf.org/literature/ |
Topic overviews (WCAG, UX, etc.) |
| Source |
URL |
Use for |
| web.dev |
https://web.dev/ |
Core Web Vitals, modern CSS, perf |
| MDN Web Docs |
https://developer.mozilla.org/ |
HTML, CSS, JS reference |
Design systems & UI (T1 / T3)
| Source |
Tier |
URL |
Use for |
| GOV.UK Design System |
T1 |
https://design-system.service.gov.uk/ |
Accessible forms, patterns |
| Material Design 3 |
T1 |
https://m3.material.io/ |
Tokens, motion, components |
| shadcn/ui |
T1 |
https://ui.shadcn.com/docs |
Composable React + Tailwind |
| USWDS |
T3 |
https://designsystem.digital.gov/ |
US gov, a11y-first |
| Shopify Polaris |
T3 |
https://polaris.shopify.com/ |
E-commerce UI + content |
| GitLab Pajamas |
T3 |
https://design.gitlab.com/ |
Open governance model |
| Ant Design |
T3 |
https://ant.design/ |
Enterprise-dense UI |
E-commerce UX (T2)
| Source |
URL |
Use for |
Note |
| Baymard Institute |
https://baymard.com/ |
Checkout, product lists, accounts |
700+ guidelines; premium |
| Baymard Learn |
https://baymard.com/learn |
Free articles |
Good for summaries |
| Baymard UX-Query |
https://baymard.com/product/ux-query |
Research-backed Q&A |
Product |
Nonprofit web & fundraising (T2)
| Source |
URL |
Use for |
| Whole Whale — Digital fundraising |
https://wholewhale.com/digital-fundraising/ |
Sequencing, Ad Grant, platforms |
| NTEN — Equitable website |
https://www.nten.org/blog/build-equitable-website/ |
Equity, accessibility, inclusion |
| NTEN Equity Guide (PDF) |
https://word.nten.org/wp-content/uploads/2021/07/NTEN-Equity-Guide-for-Nonprofit-Technology_September_2020_v2.pdf |
Technology equity |
Typography & visual craft (T2)
| Source |
URL |
Use for |
| Practical Typography |
https://practicaltypography.com/ |
Type for web and print |
Backend, API & architecture (T1)
| Source |
URL |
Use for |
| Microsoft — Web API design |
https://learn.microsoft.com/en-us/azure/architecture/best-practices/api-design |
REST best practices |
| Postman — REST best practices |
https://blog.postman.com/rest-api-best-practices/ |
Developer-oriented checklist |
| Stack Overflow Blog — REST API design |
https://stackoverflow.blog/2020/03/02/best-practices-for-rest-api-design/ |
Nouns, HTTP methods, errors |
| API/OS — Designing REST API |
https://reference.apios.info/guides/designing-rest-api/ |
Pagination, filtering, versioning |
| OpenAPI Specification |
https://spec.openapis.org/ |
Contract-first APIs |
| Twelve-Factor App |
https://12factor.net/ |
Cloud-native app methodology |
| System Design Primer (OSS) |
https://github.com/donnemartin/system-design-primer |
Large-scale concepts |
| Refactoring Guru — Design patterns |
https://refactoring.guru/design-patterns |
Software design patterns |
Security (T1)
| Source |
URL |
Use for |
| OWASP Top 10 |
https://owasp.org/www-project-top-ten/ |
Web app security baseline |
Industry directories (reference)
| Source |
URL |
Use for |
| PATH Intl — Find a Program |
https://pathintl.org/find-a-program/ |
Therapeutic riding centers (vertical research) |
How we use this index
- Topic doc cites 2–4 T1 sources with “last reviewed” date.
- Agents follow links for detail; do not paste full guideline corpora into chat.
- New sources get a PR that updates this file + one topic doc takeaway.