Microsoft recently introduced Hyperlight Wasm, a lightweight virtual machine designed to run WebAssembly (Wasm) component workloads across multiple programming languages, including C and Python. Announced on March 26, Hyperlight Wasm is implemented as a Rust library crate that executes Wasm modules within a VM-backed sandbox environment. Its main goal is to enable safe execution of untrusted or third-party Wasm code with minimal latency and overhead, leveraging hypervisor-based protection for enhanced security.
Built on the foundation of Hyperlight — an open source Rust library launched last year for running small embedded functions securely — Hyperlight Wasm supports both compiled languages like C, Go, and Rust, as well as interpreted ones such as Python, JavaScript, and C#. However, to run interpreted languages, the necessary runtime must be included in the application image. Although still experimental and not production-ready, Hyperlight Wasm harnesses the WebAssembly System Interface (WASI) and the WebAssembly Component Model to offer developers a fast, hardware-protected execution environment that is compatible across diverse platforms.
One of the key innovations of Hyperlight Wasm is its ability to execute programs compiled for the wasm32-wasip2 target using various runtimes like Wasmtime or Jco, without requiring developers to have deep knowledge of Hyperlight itself. This flexibility means that Wasm workloads can run seamlessly on servers powered by Nginx Unit, Spin, WasmCloud, or Hyperlight Wasm, simplifying deployment across different environments. Microsoft highlights that by combining Hyperlight with WebAssembly, they achieve stronger security and better performance than traditional virtual machines by reducing the amount of work required at runtime.
Looking ahead, Microsoft plans to extend Hyperlight Wasm support to Arm64 processors, broadening its applicability in diverse hardware contexts. The focus remains on leveraging WASI to ensure portability between operating systems and virtual machines, while also enhancing the developer experience by adding default bindings for key WASI interfaces. With these ongoing improvements, Hyperlight Wasm aims to become a versatile and secure foundation for running WebAssembly workloads at scale.