WTF is SDC in Drupal Core?
Single-Directory Components (SDC) is the biggest change to Drupal theming since the introduction of Twig. Here's an "unboxxing" walkthrough of how it works.
Join the "Something nice ..." newsletter
The full title is "Something nice, something quirky, something else".
I send an email once a week with something nice, something quirky, and something else that I think is interesting (all with a web development theme, of course).