They're for playing puzzley games in real time.
Each of them has a pinned message to explain the rules of the game. Anyone is welcome to take part, and the room owners tend to be people who are particularly active players of the game (or, sometimes, bots whose automatic pinning powers are necessary for playing the game).
Direct link to chatroom
I think it's important to comment first and give the authors some time to fix their answers before deleting them. Last night I went through one particularly problematic question and posted such a comment on several of the answers; by morning most of them had been improved significantly.
If you see a post without explanation, leave a comment asking them to ...
Rumkin has a pretty neat collection of cipher tools for both encrypting and decrypting
Vigenere Cipher Codebreaker can solve vigenere ciphers with or without the key. (You will need sufficiently long ciphertext to break the cipher without a key.)
Len Schulwitz is useful for encoding/decoding those pesky base 58 numbers
QuipQiup can attempt to ...
Spyfall is best played with 4 or more players.
All players are in some location. This could be a circus tent, a space station, a theater, etc. Each player is also assigned a role for the location; this might be an acrobat for the circus tent, an alien for the space station, an actor for the theater, etc. However, one player is told ...
Codenames has an espionage setting, in which players in teams try to identify their own team's secret agents, based on their agents' code names. Codenames is a game of guessing which code names (words) in a set are related to a hint-word given by another player.
The game's espionage setting explains some of ...
Contact requires at least three people, one person to create a word and at least two people to guess it. The word creator thinks of a word and gives the guessers the first letter. The guessers' objective at any stage is to get the word creator to give them the next letter of the word. They do this by coming up with words which they can (...
Assuming we want explanations (and I believe we do), this is probably the only way it's going to get enforced. Downvoting works very well when there's a culture of it, but not so well if you're the only one doing it. While I am generally against deleting content that at least attempts to be helpful, I think it may be best in the short term.
However, I'd ...
Litscape has an extensive list of words finding tools (for example pattern matching, words containing or made from certain letters, single word anagrams, etc)
Ceptimus Word Ladder solver, finds a word ladder from word A to word B
Wordsmith's Advanced Anagramming is a multilingual, multi-word anagram solver with a range of options to restrict ...
The On-Line Encyclopedia of Integer Sequences is useful for puzzles involving integer sequences
Base Converter converts between binary, decimal, hexadecimal and ASCII
Calculator Soup is a cornucopia of tools (index) for manipulating numbers in myriad contexts, even sports
Prime Factors Calculator calculates the prime factors of integers less ...
RGB Color Wheel correlates colors to RGB (#RRGGBB and 255-255-255) and HSV ( °-%-%)
GIF-Explode is a web-tool to show individual frames of animated gif images. Just provide the link to the image.
GeoGebra Tools are an online collection of tools for drawing geometries and mathematical content online.
TinkerCAD is a browser-based 3D ...
The point of encoded comments is to avoid spoilering the answer for someone who, say, accidentally scrolls down while looking at a puzzle. It's the same reason that we use spoiler markup in answers.
Unfortunately, there's no built-in way to have spoilers in comments, so people have been finding ways to create their own. For a while, people were using link ...
Chess board editor is an online interactive chessboard with PGN viewer and editor
Sudoku Solver is a fully featured sudoku solver by Andrew Stuart
Qhex Puzzle Tools contains a wide array of puzzling tools, including solving various logic puzzles (Masyu, Sudoku, Lights Out, Thermometers, Kakuro, Fill-a-Pix, Minesweeper, Hitori, Nurikabe, Tapa, ...
This is an answer to the OP's question "Whose content is it, anyway?".
I also want to make an important clarification to the OP's statement that "roughly, this (the use of the CC-by-SA licence - my note) means you can reuse SE content for any reason, as long as you attribute both SE and the original author, as well as link back to the license.&...
You can. That doesn't necessarily mean you should.
There's more to Puzzling.SE than puzzles posted as challenges for others to try to solve. While it's definitely true that these puzzle challenges are the largest share of the questions posted here, that's not because the site is all about posting puzzles for others to solve. Puzzling Stack Exchange is a ...
Yes, we should enforce explanations in answers. With downvotes and a comment linking to a faq meta post first, then deletion if the user refuses to fix the problem. Ultimately, though, to convey that we're serious about quality, deletion will need to occur, because votes are generally more a measure of popularity than quality.
Answers without explanations ...
Measure Distance on a Map measures the distance and travel time between two places, with many options such as snapping to road or not, mode of transport (including different levels of car speeds) and units to measure in.
London Underground map is a map that shows all the tube stations in London, England.
Altitude map lets you find the ...
Useful Information Sources
Telephone Dialing Codes for countries, and also shows their flags
Internet Movie DataBase for film and TV references
Runes - for all things runey
Wolfram|Alpha - computational knowledge engine
Johnny has had ten girlfriends in the past five years. He decides to plot them as a scatter plot, then arbitrarily derive them as functions of time. If Johnny had each girlfriend for a minimum of six months, how many possible data points can he have where the result of the derivative squared is greater than the original value?
--> For more questions and ...