// 01 > CONTEXT
JavaScript-Verse is a browser-based code execution environment and markdown editor for writing and running JavaScript and React, with side-by-side docs, a cheatsheet, and code export.
// 02 > THE_PROBLEM
Experimenting with JavaScript or React meant a local toolchain or a limited sandbox that couldn't pull real npm modules or render components.
Running untrusted code in the browser safely, transpiling JSX and modern syntax, and resolving imports without a server are each non-trivial, so most playgrounds punt on one of them.
Before
Local setup to experiment · no real npm modules · JSX unsupported
// 03 > APPROACH
I solved safe execution with iframe isolation, advanced syntax with in-browser Babel transpilation, and imports with in-browser bundling.
Sandboxed execution
Code runs inside an isolated iframe with live preview, so arbitrary code is safe to run.
Real modules + JSX
In-browser Babel transpiles JSX and modern syntax; in-browser bundling resolves any npm import.
// 04 > THE_RESULT
Anyone can write and run JavaScript or React in the browser, pull real npm modules, and export their code, with nothing to install.
Before
- Local toolchain required
- No npm module support
- No JSX / React rendering
After
- Runs in the browser, no install
- Any npm module at runtime
- JSX + React, sandboxed
“The fastest way to learn something is to run it. I wanted real JavaScript and React, real modules, with nothing to install first.”