Rust support is available for the NixCore X1. Rust is a low level, fast, powerful and modern language, perfect for embedded systems.
A good writeup was posted on github on how to leverage the integrated cross compiled STD library for Rust to build for supported platforms.
To build Rust for the latest LEDE 2.0 BETA 1 release use the ‘mipsel-unknown-linux-musl’ target. No runtime is required on NixCore, just copy over the binary and run.