The second runtime is the real test: a no-kernel VM from Python to Node
A new lightweight VM approach enables running 1,500 real applications on a single machine without a traditional kernel, supporting languages from Python to Node.js. The article challenges conventional server architecture by demonstrating that a "second runtime" can handle real-world workloads more efficiently than containerized or virtualized environments.
Background
Amit Limaye is a founding engineer at [Nue](https://nuejs.org), a web framework that rethinks JavaScript tooling. In this post he describes building "The Second Runtime" — a virtual machine that runs inside a Linux process (no kernel, no Docker) and can execute code in Python, Node.js, Deno, or Bun from a single host process. The key idea: instead of booting a container or VM for each runtime, you start a tiny, dedicated "runtime zone" that shares the host kernel but is isolated by Linux namespaces and seccomp. He claims the same machine can host 1,500 real web apps (each with its own runtime, filesystem, and network stack) while using far less memory than container-based approaches. The post is relevant to developers interested in lightweight sandboxing, serverless infrastructure, and the trade-offs between isolation and density.