Growing a Language, by Guy Steele (1998) [video]
Great talk, one of my inspirations.The "nub" (slightly edited):"A language design can no longer be thing.  It must be a pattern, a pattern for growth"."My point is that a good programmer does not just write programs.  A good programmer builds a working vocabulary.  A good programmer does language design, though not from scratch, but building on the frame of a base language"https://youtu.be/_ahvzDzKdB0Oh, the paper if you don't want to watch the whole thing:https://www.cs.virginia.edu/~evans/cs655/readings/steele.pdf