Well, they're both implemented in LLVM, but Julia uses a JIT and not straight to a native binary. I bet they have very similar performance. The use cases are different though. Julia is a replacement for MATLAB, R, Fortran, & scientific Python with speed and good macro support. Crystal is basically fast/native Ruby, so websites and business apps. You could technically use either for those applications, but the communities will be mostly scientific computing for Julia and business apps for Crystal.

Last time I looked Crystal's string handling was significantly slower than Ruby's.

In a pre 1.0 language there will always be some things that are still waiting to be optimized. I saw some performance spec for one of their HTTP libraries awhile back and it was a lot faster than Ruby. It might have been faster than Go.

It was faster than everything, and by a huge margin: https://github.com/costajob/app-servers#results

It does seem that immature languages tend to win a lot of benchmarks, likely because they're still cutting a lot of corners. Still, though.

I only wish they picked a more "Enterprise-friendly" name...

Well, it is the only LLVM language on the list. Even so, Nim transpiles to C and should be fairly comparable unless it is because of the async part or like you said they're cutting corners. I guess it's possible they're just that good, but it seems unlikely.

Please stop using the word transpiles in this context. Nim compiles to C.