Microsoft’s Hyperlight Wasm takes a significant step toward transforming serverless computing by leveraging the minimal hypervisor Hyperlight to create a fast, flexible platform for WebAssembly (Wasm)-based applications. Originally speculated as a potential WebAssembly-based alternative to serverless tools like Azure Functions, Hyperlight Wasm now emerges as a powerful option for developers and cloud providers looking for ultra-fast execution times and broad compatibility. This release capitalizes on two key features of the Hyperlight hypervisor: its incredible speed and the ability to host guest applications written in various languages.
Hyperlight’s performance has been a standout feature since its early demonstrations. At KubeCon North America, Microsoft showcased its ability to run a Rust-based web server on micro virtual machines (VMs) that could execute multiple functions rapidly. This speed is crucial for serverless computing, where latency is often a major concern. In the demo, the micro VMs could spin up new instances or reuse warm ones, offering microsecond response times even when serving requests from cold VMs. This kind of rapid scaling makes it a perfect candidate for serverless workloads, which require quick scaling in response to demand.
Furthermore, the flexibility of Hyperlight’s hosting environment is a critical advancement. Initially built in Rust, Hyperlight can support a variety of guest applications, not limited to just Rust. Microsoft demonstrated this by running a JavaScript interpreter written in C on the Hyperlight platform. This ability to host applications in different languages ensures that developers can leverage WebAssembly’s strengths while still having the freedom to choose the most appropriate programming language for their tasks.
However, while Hyperlight Wasm brings many promising features, it does come with certain challenges. Hyperlight serves as a virtual machine host, requiring developers to create the necessary code to load and run guest applications. Additionally, Hyperlight’s limited set of functionalities means that developers will need to rely on the WebAssembly System Interface (WASI) for compatibility. Using WASI abstracts away many complexities, enabling developers to target multiple languages and environments without needing to know the intricacies of the underlying system. This makes it much easier for developers to work with WebAssembly, while still ensuring compatibility across different platforms.
WebAssembly’s integration with Hyperlight further enhances its appeal. Developers don’t need to rely on a full Hyperlight environment to begin building or testing code, as local runtimes or WASI-ready environments such as Spin or wasmCloud can serve as development platforms. This ease of development accelerates the creation of event-driven serverless applications, and with Hyperlight’s WASI support, developers can compile languages like C or JavaScript into WebAssembly modules, significantly broadening the range of supported languages. Hyperlight Wasm, in essence, is a glimpse into the future of serverless computing, where flexibility, speed, and language diversity come together to create more efficient and scalable solutions.