Education
1,350 interactive pages · most loved first · page 35 of 57· Tonble one of these
Online Experiment on Dogmatic Thinking
A web experiment adapted from a 2020 study that tests a cognitive quirk linked to dogmatic worldviews, with a write-up o…
Online Ruler
An on-screen ruler and protractor that shows actual size in centimeters, millimeters, and inches on any device, for quic…
Online Stopwatch
A free full-screen stopwatch and countdown timer collection built for classrooms and offices, with giant readable digits…
OnThatDay.in
Pick any date between 1947 and 2025 to see the headlines, prices, people, cinema, sport and technology of India on the d…
Open Anatomy Project
A set of free, open 3D human anatomy atlases you can rotate and explore in the browser, built to give medical students e…
Open Exoplanet Catalogue
An open-source database of every confirmed exoplanet, with statistics, plots, and tools for comparing planets and their…
Open Infrastructure Map
A zoomable world map built from OpenStreetMap data showing power lines, substations, pipelines, telecom cables and other…
Open Knowledge Maps
A visual search interface that turns a research topic into a bubble map of related papers and concepts, helping you get…
Open Syllabus Galaxy
An interactive map of the million most-assigned books and articles in college courses, laid out as a glowing galaxy wher…
openDAW Studio
A free, open-source music studio that runs in the browser, letting you record, sequence and mix tracks with synths and e…
OpenHistoricalMap
An interactive map of the world throughout history, built by volunteers and dedicated to the public domain, so you can s…
OpeningTree
A chess tool that builds an opening tree from your Lichess or Chess.com games, grandmaster databases, or custom PGN for…
OpenStreetMap
The free, volunteer-built map of the world: zoom anywhere to see streets, paths and buildings mapped by locals, get dire…
OpenVim
An interactive tutorial that teaches the Vim text editor right in the browser, guiding you key by key with a virtual key…
ORBAT Mapper
A browser tool for building order-of-battle maps, placing military units on a map and animating their movements to recre…
ORBIS
Stanford's geospatial model of the Roman world that calculates the time and cost of travel between ancient cities by roa…
Origami Club: Animals
A huge free index of animal origami models - cats, frogs, cranes, dinosaurs and more - each with step-by-step diagrams a…
Origin Myth Map
An interactive world map of creation myths: browse how cultures explained the beginning of everything, from worlds wrest…
Orion Realms
A browser explorer of 220 real star systems, inspired by NASA visualization software, mixing actual astronomy data with…
oTranscribe
A free web app for transcribing recorded interviews, with a built-in audio player, keyboard shortcuts for pausing and re…
Our Solar System
A visual overview of our local neighborhood in the Orion arm of the Milky Way, with the Sun, planets, and their moons la…
Owlet BBC BASIC Editor
An in-browser editor for BBC BASIC that runs your code on an emulated 1980s BBC Micro, perfect for tiny tweet-sized prog…
Pacelock
A free Pomodoro timer built around named work blocks, flexible breaks and a distraction-capture box, designed around ADH…
Packet.School
A game-like way to learn networking, with interactive simulations, drag-and-drop network building, and a terminal experi…
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