I'll have to check it out. I'm surprised about your impression of where most lisp developers are in 2019 vs 2010 -- from my (admittedly still rather outsider) perspective the CL ecosystem looks significantly healthier in 2019 than in 2010. Clojure[Script] remains dominant but has lost a lot of steam, Racket took some high-profile Lispers but still doesn't have the production success stories that both CL and Clojure have and language progress is likely to be stalled a while as the transition to a Chez core continues, and CL usage and useful libraries have despite it all grown. The main IRC channel is active, there's a C++ integration story (Clasp), more frequent CL-related HN submissions, the European Lisp Symposium this year had a lot of new first-time attendees, and new books with an emphasis on helping production programmers (e.g. Common Lisp Recipes) were published.