String formatting with streams. It's based on new-format
$ npm install stream-format
var format = require('stream-format')
var fs = require('fs')
var index = fs.createReadStream('./index.html') // => hello world. foo: {foo}, bar: {bar}, qux: {qux}
var foo = fs.createReadStream('./foo.html') // => foo
var bar = fs.createReadStream('./bar.html') // => bar
var render = format({ foo: foo, bar: bar, qux: 'qux' });
index.pipe(render).pipe(process.stdout)
// => hello world. foo: "foo", bar: "bar", qux: "qux"