They often have horrible security, but are very small programs when you use them as wifi temperature sensors or similar. They are good targets for rewrites and greenfield applications. Right now it seems like ardunio C++ or some scripting language is the target.
Rust is a great choice in theory for anything with an LLVM target, but the libcore "bare metal"/"no standard library" ecosystem is pretty immature, and there are likely to be bugs (like the compiler generating binaries that are too large, etc). If you'd like, please try it out and file any issues you find :)
ATS is a functional programming language that does not use a garbage collector and uses dependent and linear types to do safe system programming. It provides a similar level of safety to Rust with the ability to drop down to C: http://www.ats-lang.org/
unfortunately there's no LLVM backend for the xtensa cpu used by the ESP8266. There's a gcc backend though, so if someone has the time and skillset to port to LLVM, here's a way to become a hero ;)
https://news.ycombinator.com/item?id=11148129
They often have horrible security, but are very small programs when you use them as wifi temperature sensors or similar. They are good targets for rewrites and greenfield applications. Right now it seems like ardunio C++ or some scripting language is the target.