> Actually, no. Last time I compared BEAM (Erlang) and something else, Erlang code that only parsed text data from a file (CSV) was several times slower than Perl script that parsed that, built a structure, serialized it, and wrote back to a disk file (BerkeleyDB).

Yeah, Erlang/Elixir are both not very fast when it comes to stuff like file parsing. Jose, the creator of Elixir pointed that out several times before. But as mentioned before, web developers can greatly benefit from Elixir.

> I doubt it, unless Ruby (MRI is what I think of) is an extremely poorly written interpreter.

I wrote several things in both languages. CSV parsing is pretty much the same speed, again file handling in Erlang/Elixir. When it comes to real web apps, Elixir is usually faster by a factor of 10x when DBs are involved and 100x when it comes to plain rendering.

> It's not. It's slow (I've seen it when comparing with other runtimes). It was never intended to be fast. It was always intended to be convenient and highly concurrent.

As others have mentioned, depends on what you think is fast and in what areas. When it comes to web apps, Elixir is way faster than ruby, python and even node. Pattern matching, for instance used for router matching is very fast compared to the techniques used in ruby/python frameworks.

Java, Go and several other languages are faster as Erlang/Elixir, of course. But Go is too low level for huge apps and Java is a whole different beast. Basically, Elixir is a nice middle ground to develop fast-enough web apps with high concurrency and easy scalability without sacrificing dev speed and dev fun.