Where Nimbus fits

Nimbus runs a sandbox as Worker isolates on a Cloudflare Durable Object. Compare it with microVM sandboxes such as E2B and Daytona, container platforms such as Cloudflare’s container Sandbox SDK, and in-process stub filesystems.

No native Linux software; in return, fast boots, $0 idle cost, and a disk that persists across processes.

MicroVMs and containers run native Linux software; Nimbus does not. In-process stubs stay inside the host process and give you no real toolchains. Nimbus boots in ~0.7 s median with no warm pool, costs $0 while idle, and keeps a 10 GB disk. Against the container Sandbox SDK it measured 2.6× faster on the sequential median, 0.74 s against 1.95 s. Vite HMR took 302 ms median. The benchmarks page has the method and caveats.

Nimbus’s userland began as LIFO OS by Sanket Sahu: the shell interpreter, the coreutils, and the Node.js shim. Nimbus carries that userland onto Cloudflare Durable Objects and adds per-process isolates, the SQLite-backed 10 GB disk, port routing, and the in-session toolchains.

Nimbus does not run workloads that need Docker, native wheels, GPUs, or raw TCP listeners. Capabilities & limits has the full “no” list.