Ruby but compiled for better performance. The compiler is smart and automatically detects and applies typing.

That’s from when I looked into it a bit a few months back.

It looks similar to Ruby but with an appropriately modern static type system and a macro system instead of runtime metaprogramming.

It also has its own concurrency story, as far as I remember.

The easiest way to think about it that is kinda right, and what got me into is “It’s like compiled Ruby and nearly as fast as C”.

Crystal is a language with syntax modeled after Ruby, which is considered one of the most human friendly languages (it’s way easier to understand than C and most others). Ruby and Crystal are “object oriented”. Like if you wanted to know what I had for lunch using Crystal you’d ask me, an “object” last_meal = kool_newt.stomach_contents, as where in C, you’d cut me open and look.

Where Ruby is a dynamically typed (it figures out whether things are Strings or Arrays, etc on the fly as needed, handy but very slow) scripting language, Crystal is statically typed, so you have to be conscious of types while you code. And where with ruby you end up with a script, Crystal code is compiled into a binary.

Where Ruby is good for small/medium websites with a modest traffic, or for prototyping ideas in an easy language, or making smaller utilities, Crystal can handle massive traffic, and make fast production level apps and tools without the difficulty of C or Java.

I’m using Crystal and Kemal (Kemal is akin to Ruby’s Sinatra) for web dev, and trying to make my own DNS utils (I want dnsip, not a fan of drill, dig, and other tools).

If you know Ruby, Crystal is an easy jump.