Compatibility

Native: behaves like Homebrew.
Partial: some options or packages have limits.
Unsupported: fails with an explicit error.

Cask, bundle, services and nb migrate have not yet been verified on real macOS hardware.

Feature	Status
Formulae: install, uninstall, upgrade, outdated, list, info	Native
Formulae: link, unlink, pin, autoremove, deps, uses, search	Partial (not yet verified on real macOS hardware)
Casks: app, suite, dmg, zip, tar, binary	Native (not yet verified on real macOS hardware)
Casks: hooks (`*_steps`)	Native; an unknown step or a failure rolls the install back
Casks: pkg and installer	Native (not yet verified on real macOS hardware)
Casks: upgrade	Native; self-updating casks only when named
Casks: uninstall stanza and `--zap`	Native; casks that only install a binary are not yet supported
Bundle (Brewfile)	Partial
Services	Native on macOS (launchd), labels `dev.nextbrew.<formula>`; Linux (systemd) is planned
Taps	Implemented (`nb tap`, `nb trust`); third-party taps must be trusted before they load.
Migrating from Homebrew (`nb migrate`)	Partial
Building from source	Limited coverage; developer commands (create, audit, bottle) are not planned

Command names, options and exit codes follow Homebrew. nextbrew never runs Ruby itself. A step it does not understand is reported, not skipped silently.