zeroboot

Zeroboot spawns VM sandboxes in 0.8 milliseconds — 190x faster than E2B. It pre-boots a Firecracker microVM, snapshots memory and CPU state, then forks new KVM VMs with copy-on-write memory. Each sandbox is a real VM with hardware-enforced isolation, not a container pretending to be one.

This is infrastructure for running thousands of short-lived AI agent tasks. The ~265KB memory overhead per sandbox is absurdly efficient. Compared to E2B (cloud-based, slower), Zeroboot is self-hosted and faster. Compared to nono (kernel-level process isolation), Zeroboot provides full VM isolation. Compared to Docker (container-level), you get real hardware boundaries.

Use this when you need to spin up disposable execution environments for AI agents at massive scale. Skip this unless you're running infrastructure — this is a platform primitive, not an end-user tool.

The catch: Linux-only (requires KVM), so no macOS development. The managed API is early access, and self-hosting Firecracker requires real ops knowledge. Apache 2.0 license is clean.