>> ease/speed of prototyping, pure performance, a good concurrency model > out of curiosity, which language + library/framework pairs do you think is a better t

>> ease/speed of prototyping, pure performance, a good concurrency model > out of curiosity, which language + library/framework pairs do you think is a better tool than javascript + nodejs when evaluated along each of your 3 metrics? ease/speed of prototyping: Ruby (or Python, even), Go, [Crystal] pure performance: Go, Rust, C++, C, Scala, [Crystal] a good concurrency model: Erlang, Go, [Crystal (similar to Go)] A small note about why Crystal is in brackets: The language is very young compared to the rest, and it's currently very volatile in terms of syntax/API stability, or even compiler semantics, but it looks very promising and it's quite easy to get started with it or to become a contributor because the compiler is written in itself. http://crystal-lang.org/ http://crystal-lang.org/ (Sadly, /docs is a bit outdated and misses some crucial parts, but /api is very comprehensive).