A script authored on a modern bash laptop breaks the moment it lands on Apple's frozen bash 3.2, a zsh default, or a dash container. rosetta-shell is the phrasebook that makes it speak each locale… and a conformance runner that proves the shim produces identical output in every shell, instead of hoping it does.
The gate. Runs your script under every installed shell and reports a pass/fail matrix. Exits nonzero on failure, so it drops straight into CI.
Scans a script for non-portable constructs and names the shim to use… advisory, never rewrites your code.
Localizes your environment: which shell you're in, which native features are missing.
A sourceable shim library… one portable map plus case, echo, and split shims that behave the same everywhere.
npx @flashesofbrilliance/rosetta-shellbrew install flashesofbrilliance/tap/rosetta-shellPortability-as-proof is the same discipline ARCS applies to decisions: prove a thing survives every environment instead of trusting that it will. rosetta-shell is one of the open, MIT-licensed public goods in the ARCS family… the tools are open; the ARCS intelligence that orchestrates them is private.