> Scala 3 code can use Scala 2 artifacts because the Scala 3 compiler understands the classfile format for sources compiled with Scala 2.12 and upwards. I feel

> Scala 3 code can use Scala 2 artifacts because the Scala 3 compiler understands the classfile format for sources compiled with Scala 2.12 and upwards. I feel like this isn't getting much attention but it is a huge deal. A big part of the reason that Python 3 went the way it did was users didn't want to upgrade until their libraries did and libraries didn't want to upgrade until their users did. With Scala 3, users can upgrade pretty rapidly, freeing libraries to upgrade without fear of leaving their users behind.