Dylibso raises $6.6M to help developers take WebAssembly to production

WebAssembly (Wasm for short) is an open standard that enables browser-based applications to run with near-native performance. It has also expanded to support non-browser environments, which is what is driving a lot of the recent hype around it. But like any emerging technology, it needs a stronger tooling ecosystem to realize its full potential.

One of the companies that’s pushing in this direction is Dylibso, a startup that has made it its mission to help development teams take Wasm to production. The company, which is announcing a $6.6 million seed funding round at the Wasm I/O conference in Barcelona today, made a name for itself with Extism, its open source universal plug-in system that allows developers to integrate WebAssembly into their existing non-WebAssembly codebase. It’s also launching Modsurfer, a system of record and diagnostic tool for WebAssembly, into general availability today.

The company’s funding round was led by Felicis, with participation from Boldstart Ventures, Pebblebed and Crew Capital.

Dylibso co-founder and CEO Steve Manuel previously worked at Cloudflare, where he brought Wasm support to that company’s Workers product, as well as at quantum computing startup Rigetti Computing.

Extism logo

Extism logo. Image Credits: Dylibso

“As someone who likes other languages more than JavaScript — just to put it nicely — I thought: you know, I got to use this WebAssembly runtime to bring another language to Cloudflare workers,” Manuel said. As a side project, he built a framework that compiled to WebAssembly from Rust and integrated with Cloudflare’s APIs. But in the process, he also realized that once this code was running in production, he had no real observability into how it was running, making debugging a challenge.

“There are lots and lots of places — and lots and lots of existing code and runtimes — in which developers would love to shim a little bit of their language of choice,” he explained. “WebAssembly gives you a great solution from a security and performance standpoint to be able to run that code reliably inside another environment, but compiled from a different language.”

And that’s the core of the idea behind Extism, which Dylibso launched in December 2022. It’s an open source plug-in system that allows developers to run any code that can be compiled to WebAssembly inside of any program that’s previously been written in a different language. “The goal is really to make it as easy as possible to integrate WebAssembly into your program, whether your program already uses Wasm or not. Doesn’t matter. It makes it easy to do,” Manuel said. He stressed that it is not a commercial product but primarily meant to accelerate the adoption of WebAssembly — especially for code that runs outside of the browser.

Modsurfer aims to fix Manuel’s other problem: understanding how WebAssembly code runs in production — and why it may fail. It’s available for free to developers, but it’s also Dylibso’s first commercial product, as it will offer an enterprise version of Modsurfer as well.

Image Credits: Dylibso

“Modsurfer gives you this single pane of glass for all of the WebAssembly code that you’re interested in and keeping track of,” Manuel explained. It’s meant to be part system-of-record, allowing developers to keep track of all of the WebAssembly code they are running, and part analysis tool for this code. Since WebAssembly is a binary format, the code sits in a bit of a black box that Modsurfer aims to crack open these modules for developers. It analyzes the code (and can often detect what language it was originally written in) and returns data about its complexity, imports and exports, namespaces and more. “We analyze and conduct what’s called a cyclomatic complexity analysis, where we actually determine the risk profile of running this code in your environment,” said Manuel.

Modsurfer is now generally available.

Image Credits: Dylibso

“Developers often struggle to use WebAssembly due to the technology’s lack of tooling,” said Paul Nashawaty, principal analyst, Enterprise Strategy Group. “We are seeing in our research and expect the market for WebAssembly and its value to developers to rival — if not be larger — than container adoption, but the right tools need to be available to help developers through the entire development lifecycle and bring WebAssembly into production. Dylibso enables developers to easily use WebAssembly with a suite of products that help them integrate WebAssembly and gain critical insight and visibility into their binary code.”