Forge

Forge is an experimental JavaScript runtime built on Mozilla's SpiderMonkey engine.

The project focuses on building a modern JavaScript runtime from the ground up with a native, high-performance architecture instead of layering new APIs over existing runtimes.

Status: Early development

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Current Progress

✅ Completed

• SpiderMonkey integration
• Forge Core foundation
  • Types
  • Error
  • Result / ResultVoid
  • Assert
  • Allocator
  • UniquePtr
  • Vector
  • String
  • StringView
  • Span
  • Array
  • Queue
  • Stack
  • HashMap
  • HashSet
• Native Windows IOCP Event Loop
• ThreadPool
• Timers
  • setTimeout()
  • setInterval()
  • clearTimeout()
• Microtask queue
  • queueMicrotask()
• JavaScript Filesystem API
  • fs.readFileSync()
  • fs.writeFileSync()
  • fs.appendFileSync()
  • fs.existsSync()
  • fs.mkdirSync()
  • fs.rmSync()
  • fs.statSync()
• 29 runtime self-tests
• Benchmark suite

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Current Platform

• ✅ Windows x64

Linux and macOS support are planned.

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Running

Create a file:

print("Hello Forge!");

Run it:

forge.exe hello.js

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Benchmarks

Benchmark	Forge	Bun	Node	Winner
Startup	19.65 ms	38.93 ms	43.62 ms	🥇 Forge
JSON	368.79 ms	249.93 ms	546.43 ms	🥇 Bun
Loop	81.98 ms	71.56 ms	90.95 ms	🥇 Bun
Timers	24.13 ms	49.44 ms	59.55 ms	🥇 Forge
Microtasks	55.93 ms	54.71 ms	108.69 ms	🥇 Bun
Promise Chains	88.84 ms	44.23 ms	48.02 ms	🥇 Bun
Filesystem	810.60 ms	990.25 ms	918.78 ms	🥇 Forge

Current Highlights

• 🚀 Fast startup
• ⏱️ High-performance timers
• 📁 Fast synchronous filesystem API
• ⚡ Microtasks close to Bun
• 🎯 Promise chains are the primary optimization target

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Roadmap

The next major milestones are:

• Async Filesystem (fs.readFile, fs.writeFile)
• Networking API
• HTTP Server
• Module System
• Worker Threads
• Performance optimization
• Node.js compatibility
• Linux support
• macOS support

See ROADMAP.md for the complete roadmap.

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License

MIT