Browser runtimes for AI coding CLIs, Node.js, Python, C/C++, Java, Flash, and x86 binaries via WebAssembly.
Interested in any of our technologies, or generally in compilers, virtual machines, or WebAssembly?
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Sandboxed runtimes for browser-based execution
Website · Repository · Documentation
- Entirely client-side: instant startup
- Language support: Node.js available. Python and Ruby support planned.
- Supports inbound and outbound networking
- Expose HTTP endpoints publicly using Portals
- Run multiple processes or services in parallel with true concurrency
- Embed coding CLIs in your web project
- Persistent filesystem stored locally in the browser
- Ideal for interactive tutorials, quick experiments, and shareable development environments
Run AI coding CLIs in the browser, client-side
- Supports Claude Code and Gemini CLI, with Codex and OpenCode coming soon
- Runs at native speed with instant startup
- Includes command line tools like bash and git
- Free and open source
A serverless Linux environment running in the browser, client-side
- Built on CheerpX, our x86 virtualization engine
- Run a full Linux userspace, terminal and tools included
- Full in-browser networking support through Tailscale
- Supports custom images
- Claude Computer Use support
- A complete Linux desktop environment in WebVM 2.0
A WebAssembly-powered x86 virtual machine for the browser
Website · Repository · Documentation
- Execute unmodified x86 binaries from JavaScript 🤯
- Safe sandboxed execution fully client-side
- Includes a x86-to-WebAssembly JIT compiler, a virtual block-based file system, and a Linux syscall emulator
- The engine behind WebVM
- CheerpX for Flash: See Flash content in modern browsers by running Flash Player via CheerpX
A Java Virtual Machine and runtime for the browser, backed by WebAssembly
Website · Repository · Documentation
- 100% compatible with Java 8
- Full runtime environment for applications, applets, libraries, and Java Web Start / JNLP applications
- Run any Java library from JavaScript using only its JAR file
- Java-JavaScript interoperability
- Swing and AWT Support
- Compile and run Java in the browser
An open-source C/C++ compiler that emits WebAssembly and JavaScript
Website · Repository · Documentation
- Port C/C++ libraries to the browser for use in JavaScript
- Write your web application in high-performance C++
- Emits best-optimised output without external tooling
- Stays up-to-date with LLVM/Clang upstream
