Skell is a very very very barebone shell written in Rust. It cannot do much unfortunately, but it can be used to open Emacs so it shouldn't matter.
Basic shell commands like cd work. You can launch pretty much anything coved in PATH. grep and ag don't work as of now so it's a big deal breaker.
This was a fun experiment with Rust and by no means is intended to replace your present shell.
If you want to take it out for a spin, here is what you do
https://github.com/Kriyszig/skell.git
cd skell
rustc main.rs
./main