I'm not sure if Rust is a proper comparison, as the standard library for a language for scientific and technical computing is much larger than a language for sy

I'm not sure if Rust is a proper comparison, as the standard library for a language for scientific and technical computing is much larger than a language for systems programming: you want a vast vocabulary to deal with matrices as opposed to a minimalist set of orthogonal features for systems programming. Another consideration: with Julia, it aims to be both a full-featured programming language (with a type system and support for metaprogramming for library developers), as well as approachable enough for a scientist to pick up.