detect-node

$3

``shell
npm install --save detect-node
`

$3

`js
var isNode = require('detect-node');

if (isNode) {
console.log("Running under Node.JS");
} else {
alert("Hello from browser (or whatever not-a-node env)");
}
`

The check is performed as:
`js
module.exports = false;

// Only Node.JS has a process variable that is of [[Class]] process
try {
module.exports = Object.prototype.toString.call(global.process) === '[object process]'
} catch(e) {}

`

Thanks to Ingvar Stepanyan for the initial idea. This check is both the most reliable I could find and it does not use process` env directly, which would cause browserify to include it into the build.