Observed arrival · 2026-09-07
Programming Encyclopedia You Can Run
A Japanese programming reference that lets readers edit, execute, and inspect code examples directly in the browser.
Field notes
The homepage pairs reference-style explanations with an editable JavaScript playground: readers can alter the sample, run it with the button or Ctrl+Enter, inspect output, and restore the original. The page states that examples are checked against their output before publication and that user code remains inside a browser sandbox rather than being sent to the server. It also describes recorded execution traces for languages that cannot run in-browser and comparisons of one operation across eight languages.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
One card from the complete issue