"Java needs to die."
Citation needed? Say you need to write fast, concurrent server-side code. What language do you choose, if not Java? Go or Erlang? C++?
Citation needed? Say you need to write fast, concurrent server-side code. What language do you choose, if not Java? Go or Erlang? C++?
Clojure or Scala might be acceptable (Java VM).
Does Javascript even have concurrency constructs?
Solr, for a random example, would not be a good task for either Python or Javascript, there are tricky concurrency concerns involving your index reads/writes and they're both just-plain-not-fast-enough. The only dynamic language I know of that isn't just embarrassingly slow compared to Java is Lua, due to some extreme fanciness on the part of their VM.