Explore the concept of parasitic programming languages in this insightful conference talk from Philly ETE 2017. Delve into the benefits and tradeoffs of piggybacking on mature language runtimes and existing ecosystems. Examine the success of languages like Scala and Clojure on the Java Virtual Machine, and the rise of compile-to-JavaScript languages. Focus on the Clojure and ClojureScript projects, discussing their development and impact. Learn about fixed ideas in programming, cost-benefit analysis in language design, and the future of functional programming. Investigate the potential of WebAssembly and other compilation targets. Gain valuable insights into design decisions, popular packages, and the evolving landscape of programming languages.