Actually learn something

Fly out through a mapped model of our stellar neighbourhood until the Sun is one unremarkable dot among thousands.

The Myers-Briggs-flavoured test everybody has taken, with a four-letter verdict and profile pages that are unnervingly specific.

The original tile-merging game, written in a weekend and responsible for an enormous amount of lost 2014.

Grant Sanderson's maths lessons, plus the written versions of the animations that made linear algebra look like geometry.

Seventy statements, four political axes and an ideology label at the end. The open-source template for a hundred imitators.

Enormous free MUD with hundreds of areas and a browser client, so you can be killed by a wandering mob without installing anything.

Photographic essays on ruined institutions that are far more interested in why the places closed than in the broken glass.

Twenty-eight escalating trolley dilemmas that end somewhere very silly, each showing the percentage of people who agreed with you.

Text MUD running continuously since 1997, with a player-run economy, real politics and a genuinely intimidating combat system.

Thousands of free electronics tutorials with full wiring diagrams and working code. The gentlest on-ramp to microcontrollers there is.

The proper colour wheel — analogous, triadic, split complementary — plus contrast checks for accessibility.

Unfiltered aircraft tracking, including the private jets and military flights that the commercial trackers politely agree to hide.

Janelle Shane feeds neural networks recipes, paint names and knitting patterns, then reports the wreckage with real affection.

Buy aircraft, plot routes and slowly discover that fuel price is the only variable that ever really mattered.

A famously unforgiving airline simulation that keeps running in real time whether or not you are logged in to watch.

The lab page of the psychologist whose completely static images refuse to stop rotating, added to for over twenty years.

Professional reviews, genre family trees and similar-artist chains inherited from the print era, which is how you get from one band to fifty.

Free MUD with multiclassing, a web client and a player base that has been levelling the same characters since the nineties.

Genuine industrial surplus sold with the best product copy on the internet: lab glassware, small motors, and 400 unexplained springs.

Fingerprints your browser and compares it against a research dataset of hundreds of thousands of others. The verdict is usually: unique.

Type your address and spin the globe back 750 million years to see where that ground sat, and which ocean was sitting on top of it.

Obsessively detailed database going down to individual episode credits and file hashes. Built for cataloguers, not for browsing.

Industry news since 1998, plus an encyclopedia with staff and voice credits that nothing else in the space matches.

The spaced repetition flashcard system serious learners settle on, with shared decks for nearly every subject.

The prestige-layer masterpiece: reset everything for a multiplier, then reset the resets, until the numbers stop having names.

Apple II software preserved and emulated, including the educational titles that an entire generation met at school.

Gianni Sarcone's workshop of puzzles and illusions, half optical trickery and half mathematical recreation, running since the 1990s.

Thousands of themed collections built by libraries and museums, each one somebody's deliberate decision about what to keep.

The Portuguese web archive, notable for full-text search across its whole history rather than only address lookup.

The preprint server where most physics, maths and computer science appears long before a journal touches it.

Draws boxes, arrows and flowcharts entirely out of monospace characters, for diagrams that live inside code comments.

Recorded terminal sessions replayed as selectable text, genuinely useful to learn from and indistinguishable from real work.

Weekly writing on current transits that assumes you want the mechanics rather than the vibes. Unusually technical for the genre.

Wiki of some seventy thousand birth charts with sourced birth times, each graded by how reliable the underlying record is.

Free birth charts, synastry and transit calculators with more configuration options than most paid software. No account required.

The Swiss Ephemeris people: the technical reference the whole field quietly runs on, plus free charts and very long interpretation texts.

Susan Miller's famously long monthly forecasts — several thousand words per sign, published without fail since 1995.

One astronomy image a day since 1995, each with a paragraph from an actual astronomer and an archive going back decades.

A gazetteer of the world's odd corners — bone chapels, abandoned observatories, restaurants built inside caves.

The industry's awards site, and the fastest way to find out what the ambitious end of web design is doing this month.

Backgammon against ranked humans, with an analysis pass afterwards that quantifies precisely how reckless your doubles were.

Engineering essays with live diagrams you drag — gears, lenses, GPS, sound — each the clearest thing ever written on its subject.

Run a basketball franchise through thirty simulated seasons in an afternoon: drafts, trades, contracts and ageing, all free.

Eight hours on the networks that existed before the internet reached homes, released free by the person who made it.

Annual contest in which vision scientists compete to fool you, with every finalist since 2005 still watchable.

Maths explained by intuition first and formulas second, by someone who clearly resented how he was taught it.

India's monuments, crafts and regional history laid out as something you explore rather than something you revise.

The personality model psychologists actually use, in a clean 120-question version with a proper breakdown of every facet.