Serdar is a CTO at Twentify, experienced Rubyist from Turkey, and a Crystal evangelist. So if you have no faith in Crystal, there is a good chance Serdar will persuade you otherwise. He is also an author of Kemal http://kemalcr.com. And a frequent speaker at various Ruby conferences. For more information please visit his personal blog http://serdardogruyol.com/ or go through our short interview, where we take a closer look on his love story with Crystal.
It was June 2015 and i heard this Ruby-ish language called Crystal. Wrote a simple Ruby program and ran it with Crystal without any changes and that's when i fell in love with it :) After that encounter, I started to use and promote Crystal. Founded Crystal Turkey, wrote Crystal for Rubyists, curated Crystal Weekly and created Kemal.
Crystal is great! It's a unique programming language which combines Ruby-like beauty with C speed. It's a testament that you can have a programming language which is so beautiful yet so fast. I believe that's a dream came true for a lot of Rubyists like me. However Crystal is not just for Rubyists, it's for everyone :)
Crystal uses LLVM. When a Crystal program gets compiled LLVM does a lot of optimizations and compiles the program into native code.
Crystal shines when your program is doing a lot of CPU intensive tasks. In those cases Crystal is order of magnitudes faster than Ruby. However it's not always about being faster, Ruby is awesome <3
I believe that 2017 will be a great year for Crystal. Hopefully we'll have a 1.0 release which will make Crystal officially production-ready. Being production-ready will make Crystal more feasible for big companies and will definitely help gaining more users/contributors/sponsors.
Kemal is not a Rails-like framework. It's minimal, modular and fast which is more Sinatra-ish. Though it's not correct to directly compare Kemal with Phoenix, we can easily say that both are blazing fast!
See also Serdar’s article: “An Introduction to Crystal: Fast as C, Slick as Ruby”