Dash

The Dash shell is a modern POSIX-compliant shell implementation. It is typically used as /bin/sh. This is because it is faster other shell implementations, such as Bash. It is roughly four times faster than Bash, uses little system resources, and is quite secure being a simple and long established codebase.

On some Linux distros, such as Ubuntu, it is already the used as /bin/sh. However on distros such as Arch, by default bash is used instead. So to set it as /bin/sh either the dash or dash-static-musl package must be installed and then dash symlinked to /bin/sh. The AUR package dashbinsh provides this automatically instead of having to do it manually.

For more info read: https://wiki.archlinux.org/title/Dash