Curated discovery

Hidden Gems Directory

A bilingual discovery engine for useful, weird, under-linked places on the web.

Featured hidden gems

Small but dense: every gem needs source context, a use case, and a way to start.

Topics

Excalidraw

excalidraw.com

An open source whiteboard for sketchy diagrams, quick architecture maps, and collaborative visual thinking.

Have I Been Pwned

haveibeenpwned.com

A practical breach lookup service for checking whether an email address appears in known data breaches.

NASA Eyes

eyes.nasa.gov

Interactive 3D experiences for exploring planets, missions, and Earth systems.

oldweb.today

Browse archived websites through emulated vintage browsers.

Photopea

www.photopea.com

A browser-based image editor that opens many professional design and image file formats.

Public Work

public.work

A compact search surface for public domain images from museum and library collections.

Radio Garden

radio.garden

Spin a globe and listen to live radio stations from cities around the world.

Seeing Theory

seeing-theory.brown.edu

An interactive visual introduction to probability and statistics concepts.

This week’s brief

Week 28 Lucky Brief

A compact weekly note for one useful public domain image source and one source-checking rabbit hole.

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Put a useful under-linked find into the review queue.

Open source gemsHuman reviewed

Excalidraw

An open source whiteboard for sketchy diagrams, quick architecture maps, and collaborative visual thinking.

Why worth a look: it makes public-domain archives feel browsable while keeping source context close.

PricingFree

API availableNo

Last checked2026-07-08

Good for

Explaining an idea before turning it into a polished diagram.Sharing rough architecture or product flows quickly.

Also worth opening

Have I Been Pwned NASA Eyes oldweb.today

View detail Open original

One Useful Rabbit Hole30 minutes

Build a Useful Browser Toolkit Without Signing Up

A 30-minute path for turning four unusual browser tools into a small, reusable bookmark kit for everyday problems.

Save a visual time-zone checkUse Every Time Zone to compare two working hours, then write down the meeting window the visualization makes easiest to understand.
Add one account-safety checkUse Have I Been Pwned for an address you are authorized to check, then note the next concrete action without saving private results.
Prove a browser editor can finish a small taskOpen a copy of a non-sensitive image in Photopea, make one small edit, and export the result before committing to a longer workflow.

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Explore the library

Structured discovery routes for people, search engines, and AI answer engines.

Topics6 curated lanes

Browse AI tools, public data APIs, public-domain assets, open-source gems, interactive explainers, and weird useful websites.

RSS + JSON feeds
Intent filters
Fresh gem clusters

Browse topics BriefsShort editorial notes

Weekly source checks with selection criteria, reusable summaries, and links worth citing.

3-minute reads
Source checked
Shareable summaries

Read briefs Rabbit holesGuided discovery paths

Step-by-step routes through related tools, public sources, and repeatable research workflows.

30-45 minute paths
Related gems
Practical outcomes

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