APLcart

APLcart is the largest-ever collection of short APL phrases, comprising over three thousand idiomatic expressions from Dyalog APL, FinnAPL, and APL2, and lots of other sources, including the community at large. It was created by Adám Brudzewsky who also maintains the site, but incorporates content and suggestions from the community through GitHub pull requests and templated issues.

The service was created in reaction to the lack of resources to answer "how-to" questions from both beginners and professionals. This is in contrast to several ways to access the available documentation suites and ways to access them. For example, in many IDEs, one can press the F1 key while the caret is pointing at a primitive function or Quad name to open the appropriate documentation.

In addition to functioning as a look-up service, APLcart also provides training through its quiz page, including:
 * Writing a function for a given task
 * Explaining the purpose of a given function
 * Filling in an obscured symbol