Shuru is a lightweight sandbox that spins up Linux VMs on macOS using Apple's Virtualization.framework. Boots in about a second on Apple Silicon, and everything is ephemeral by default. There's a checkpoint system for when you do want to persist state, and sandboxes run without network access unless you explicitly allow it. Single Rust binary, no dependencies. Built it for sandboxing AI agent code execution, but it works well for anything where you need a disposable Linux environment.