
> **Note**: This list includes [some sites](https://en.wikipedia.org/wiki/Shadow_library) that have concerns over legality and copyright issues. In all such known cases, the corresponding Wikipedia page has been linked, instead of linking directly. Before proceeding, please read [this thread](https://academia.stackexchange.com/questions/112509/legality-of-downloading-books-from-websites-such-as-library-genesis) on Stack Exchange.

## Ebooks

- [EbookFoundation/free-programming-books](https://github.com/EbookFoundation/free-programming-books)
- [zero-equals-false/awesome-programming-books](https://github.com/zero-equals-false/awesome-programming-books) - A curated list of awesome programming books.
- [OpenStax](https://openstax.org/)
- [Wikibooks](https://en.wikibooks.org/wiki/Main_Page)
- [Archive.org](https://archive.org/)
- [Project Gutenberg](https://www.gutenberg.org/)
- [fadedpage.com](https://www.fadedpage.com/)
- [Standard Ebooks](https://standardebooks.org/)
- [The Internet Classics Archive](http://classics.mit.edu/) - Bringing the wisdom of the classics to the Internet since 1994.
- [MIT OCW Index of Online Textbooks](https://ocw.mit.edu/courses/online-textbooks/)
- [The Online Books Page - University of Pennsylvania](https://onlinebooks.library.upenn.edu/)
- [Textbooks](https://textbooks.cs.ksu.edu/) - Kansas State University Department of Computer Science
- [Open Textbook Library](https://open.umn.edu/opentextbooks/)
- [Global Grey Ebooks](https://www.globalgreyebooks.com/) - A curated catalogue of public-domain classics.
- [Electronic References - Colin Stebbins Gordon](https://csgordon.github.io/books/)
- [freecomputerbooks.com](http://freecomputerbooks.com/)
- [HN Search 'books'](https://hn.algolia.com/?dateRange=all&page=0&prefix=true&query=books&sort=byPopularity&type=story)
- Math
  - [List of websites, ebooks, downloads, etc. - r/learnmath](https://www.reddit.com/r/learnmath/comments/8p922p/list_of_websites_ebooks_downloads_etc_for_mobile/)
  - [Open Textbook Initiative - AIM](https://aimath.org/textbooks/)
  - [Real Not Complex](https://realnotcomplex.com/) - Discover incredible free resources to study mathematics.
- [Library Genesis](http://en.wikipedia.org/wiki/Library_Genesis)
- [Anna's Archive](https://en.wikipedia.org/wiki/Anna%27s_Archive)
- [The Pirate Bay](https://en.wikipedia.org/wiki/The_Pirate_Bay)
- [ZLibrary](https://en.wikipedia.org/wiki/Z-Library)
- IRC
  - `#Bookz` on Undernet
  - `#ebooks` on Undernet
  - `#ebooks` on IRChighway

## Research papers

- [Best Paper Awards in Computer Science](https://jeffhuang.com/best_paper_awards/)
- [papers-we-love/papers-we-love](https://github.com/papers-we-love/papers-we-love) - Papers from the computer science community to read and discuss. https://paperswelove.org.
- [PeerJ](https://peerj.com/) - Peer-reviewed & Open Access journal publishing primary research and reviews in biology, life sciences, environmental sciences, and medicine.
- [unpaywall.org](https://unpaywall.org/) - An open database of millions of free scholarly articles. 
- [arXiv.org](https://arxiv.org/)
- [Google Scholar](https://scholar.google.com/)
- [#ICanHazPDF](https://en.wikipedia.org/wiki/ICanHazPDF)
- [lmfdb.org](http://www.lmfdb.org/) - The L-functions and modular forms database.
- [Sci-Hub](https://en.wikipedia.org/wiki/Sci-Hub)

## Audiobooks

- [LibriVox](https://librivox.org/) - Free public domain audiobooks.
- [Lit2Go](https://etc.usf.edu/lit2go/) - Free online collection of stories and poems in mp3. 
- [Audible](https://www.audible.co.uk/) `paid`
- [The Project Gutenberg Open Audiobook Collection](https://marhamilresearch4.blob.core.windows.net/gutenberg-public/Website/index.html) - Audiobooks created using neural text-to-speech technology by Microsoft and MIT.


Ebooks and research papers

[Top]

Ebooks

Research papers

Audiobooks


## Rubik's Cube

- [JPerm.net](https://jperm.net) - By Dylan Wang.
- [CubeSkills](https://www.cubeskills.com/) - By [Feliks Zemdegs](https://en.wikipedia.org/wiki/Feliks_Zemdegs).
- [AlgDb.net](http://algdb.net/) - Rubik's Cube Algorithms Database.
- [Speed Cube Database](http://speedcubedb.com/)
- [Speedsolving Wiki](https://www.speedsolving.com/wiki/index.php/Main_Page)
- [Ruwix](https://ruwix.com/)
- [Andy Klise](http://www.kungfoomanchu.com/) - Illustrations and Algorithms.
- [cubing.net](https://cubing.net/)
- [Badmephisto's Cubing Site](http://badmephisto.com/)
- [Best site ever](https://bestsiteever.ru/)
- [CubeRoot](https://www.cuberoot.me/)
- [Cubefreak](http://cubefreak.net/)
- [cut-the-knot.org](https://www.cut-the-knot.org/) - Interactive Mathematics Miscellany and Puzzles.
- Timers
  - [csTimer](https://www.cstimer.net/) ([Source](https://github.com/cs0x7f/cstimer))
  - [qqTimer](https://www.qqtimer.net/) ([Source](https://github.com/cubing/qqtimer)
  - [Twisty Timer](https://play.google.com/store/apps/details?id=com.aricneto.twistytimer) ([Source](https://github.com/aricneto/TwistyTimer)) (Android)
  - [timer.cubing.net](https://timer.cubing.net/) ([Source](https://github.com/cubing/timer))
  - [Timiks](https://timiks.com/) ([Source](https://github.com/ngerritsen/timiks))
  - [cTimer](http://www.ctimer.co.uk/) by Conrad Rider
  - [Ruwix Timer](https://ruwix.com/online-rubiks-stopwatch-timer/)
- People
  - [Stefan Pochmann](https://www.stefan-pochmann.info/)
  - [Lucas Garron](https://garron.net/)
  - [Jessica Fridrich](http://www.ws.binghamton.edu/fridrich/)
  - [Herbert Kociemba's Homepage](http://kociemba.org/)
  - [Lars Petrus Portal](https://lar5.com/)
  - [Erich Friedman](https://erich-friedman.github.io/) - Prof. Erich Friedman's webpage.
  - [Cubewhiz.com](http://www.cubewhiz.com/) - Bob Burton.
- Fun
  - [You know you've been cubing too long when ...](https://cube.garron.us/misc/too_long.htm)
  - [Frank Morris Facts](https://cube.garron.us/misc/frank_morris.htm)

## Chess

- [Lichess](https://lichess.org) ([Source](https://github.com/ornicar/lila))
- [Chess.com](https://www.chess.com/)
- [chess24.com](https://chess24.com/en)
- [Kasparovchess](https://kasparovchess.com/)
- [ChessBase](https://en.chessbase.com/)
- [Chessgames.com](https://www.chessgames.com)
  - [Notable Chess games of all time](https://www.chessgames.com/perl/goat.pl)
- [Chess tactics explained](https://www.chesstactics.org/)
- [Who will win in this riveting game of Math.random() vs Math.random()?](https://chessboardjs.com/examples#5002)
- [Shogi (Japanese chess)](https://en.wikipedia.org/wiki/Shogi)
- [Xiangqi (Chinese chess)](https://en.wikipedia.org/wiki/Xiangqi)
- [Jannggi (Korean chess)](https://en.wikipedia.org/wiki/Janggi)
- [Chessable](https://www.chessable.com/)
- [Chess Tempo](https://chesstempo.com/)
- [Listudy](https://listudy.org/en) ([GitHub](https://github.com/ArneVogel/listudy))
- [KungFuChess](https://kungfuchess.org/)
- [Plaskett's Puzzle](https://en.wikipedia.org/wiki/Plaskett%27s_Puzzle)
- [Puzzle: White to play and avoid giving mate](https://en.wikipedia.org/wiki/Karl_Fabel)
- [Knight's tour](https://en.wikipedia.org/wiki/Knight%27s_tour)
- [Eight queens puzzle](https://en.wikipedia.org/wiki/Eight_queens_puzzle)
- [Shannon number](https://en.wikipedia.org/wiki/Shannon_number)
- [Winning with the Bongcloud](https://i.4pcdn.org/tg/1401479151063.pdf)
- [wtharvey.com](https://wtharvey.com/)
- [The Immortal Chess Problem](https://www.chesshistory.com/winter/extra/bayer.html)

## Go

- [OGS](https://online-go.com) ([Source](https://github.com/online-go/online-go.com))
- [KGS](https://www.gokgs.com/)
- [Sensei's Library](https://senseis.xmp.net/)
- [PlayGo.to](https://playgo.to/en)

## Sudoku

- [Sudoku Coach](https://sudoku.coach/)
- [Sudopedia](http://www.sudopedia.org/)
- [SudokuWiki](https://www.sudokuwiki.org/)
- [HoDoKu](https://hodoku.sourceforge.net/)
- [SudokuExchange](https://sudokuexchange.com/play/) ([GitHub](https://github.com/grantm/sudoku-web-app))
- [f-puzzles](https://www.f-puzzles.com/)
- [Penpa+](https://swaroopg92.github.io/penpa-edit/) ([GitHub](https://github.com/swaroopg92/penpa-edit))
- [Phistomefel Ring](https://crackingthecryptic.fandom.com/wiki/Phistomefel_Ring)

## Hex

- [Hex Stategy Guide](http://www.mseymour.ca/hex_book/hexstrat.html)

## KenKen

- [KenKen Puzzle](http://www.kenkenpuzzle.com/)

## Misc

- [World Puzzle Federation](https://worldpuzzle.org/)
- [BoardGameGeek](https://boardgamegeek.com/) - Gaming Unplugged Since 2000.
- [Pagat.com](https://www.pagat.com/)
- [Futility Closet](https://www.futilitycloset.com/)- An idler's miscellany of compendious amusements.
- [Mahjong](https://en.wikipedia.org/wiki/Mahjong)
- [Bingo](<https://en.wikipedia.org/wiki/Bingo_(American_version)>)
- [Jenga](https://en.wikipedia.org/wiki/Jenga)
- [Tafl games](https://en.wikipedia.org/wiki/Tafl_games)
- [Nine dots puzzle](https://en.wikipedia.org/wiki/Nine_dots_puzzle)
- [Cat's cradle](https://en.wikipedia.org/wiki/Cat%27s_cradle)
- [Slothouber–Graatsma puzzle](https://en.wikipedia.org/wiki/Slothouber%E2%80%93Graatsma_puzzle)
- [Wolf, goat and cabbage problem](https://en.wikipedia.org/wiki/Wolf%2C_goat_and_cabbage_problem)
- [Trachtenberg system](https://en.wikipedia.org/wiki/Trachtenberg_system)
- [Rätsel, Puzzles und anderer Denksport kostenlos mit Lösungen](https://www.janko.at/Raetsel/index.htm)
- [Nikoli Puzzle](https://www.nikoli.co.jp/en/puzzles/)
- Puzzles
  - Crossword
  - Zigsaw
  - [2048](<https://en.wikipedia.org/wiki/2048_(video_game)>)
  - [Kakuro](https://en.wikipedia.org/wiki/Kakuro)
  - [Masyu](https://en.wikipedia.org/wiki/Masyu)
  - [Soma cube](https://en.wikipedia.org/wiki/Soma_cube) and [similar puzzles](https://en.wikipedia.org/wiki/Soma_cube#Similar_puzzles)
- Logic puzzles
  - [Zebra Puzzle](https://en.wikipedia.org/wiki/Zebra_Puzzle)
  - [Verbal arithmetic](https://en.wikipedia.org/wiki/Verbal_arithmetic)
- Board games
  - Hive
  - Stratego
  - [Checkers](https://en.wikipedia.org/wiki/Checkers)
  - [Backgammon](https://en.wikipedia.org/wiki/Backgammon)
  - [Monopoly](<https://en.wikipedia.org/wiki/Monopoly_(game)>)
  - [Uno](<https://en.wikipedia.org/wiki/Uno_(card_game)>)
  - [Crokinole](https://en.wikipedia.org/wiki/Crokinole)
  - [GHQ](https://boardgamegeek.com/boardgame/422478/ghq) - Kurt Vonnegut's Lost Board Game
- Card games
  - [Poker](https://en.wikipedia.org/wiki/Poker)
  - [Bridge](https://en.wikipedia.org/wiki/Contract_bridge)
  - Blackjack
  - Spades
  - Solitaire
  - Rummy
  - Crazy Eights
  - Go Fish
- Pen and pencil games
  - Sprouts, Sim, Nim, Hangman, Dots, Dots and Boxes, Paper Soccer, Battleships, Beetle, Pictionary, Categories, Bulls and Cows, TwixT
- Misc: Wordle, Dominoes

