Several years ago, I worked on some open source projects that involved Racket. The community and Matthew Felleisen in particular were very helpful, and it sticks with me that the project founder took time to teach me idiomatic/correct ways to write Racket code and tests.

Not condoning Matthew Felleisen's behavior towards Matthew Butterick - people deserve to be treated with dignity and respect - but there does seem to be a side to M.F that enjoys teaching and evangelizing Racket.