The JS source from "Juan Benet: Enter the Merkle Forest" (https://youtu.be/Bqs_LzBjQyk)

demo.js

/*
 * Construction of the blocks with IPLD
 */

var ipld = require('ipld')

var obj1 = { "data": "Hello " }
var obj1Data = ipld.marshal(obj1)
var obj1Hash = ipld.multihash(obj1Data)

> obj1Data.toString('base64')
oWRkYXRhZkhlbGxvIA==
> obj1Hash
QmUUuaD...Z88Bg

var obj2 = { "data": "World\n" }
var obj2Data = ipld.marshal(obj2)
var obj2Hash = ipld.multihash(obj2Data)

> obj2Hash
QmSVuc2...ydAHV

var obj3 = { 
  "file": [
    { "/": "QmUUuaD...Z88Bg" },
    { "/": "QmSVuc2...ydAHV" },
  ]
}
var obj3Data = ipld.marshal(obj3)
var obj3Hash = ipld.multihash(obj3Data)

> obj3Hash
QmdhMzs...FcAhw


/*
 * Adding the block to an IPFS node
 */

var ipfs = require('ipfs')

ipfs.add(obj1)
ipfs.add(obj2)
ipfs.add(obj3)

/*
 * Getting the blocks from the IPFS P2P network
 */
> ipfs.resolve("QmUUuaD...Z88Bg")
{ "data": "Hello " }
> ipfs.resolve("QmSVuc2...ydAHV")
{ "data": "World\n" }

> ipfs.resolve("QmUUuaD...Z88Bg/data")
"Hello "
> ipfs.resolve("QmSVuc2...ydAHV/data")
"World\n"

> ipfs.resolve("QmdhMzs...FcAhw")
{
  "file": [
    { "/": "QmUUuaD...Z88Bg" },
    { "/": "QmSVuc2...ydAHV" },
  ]
}

> ipfs.resolve("QmdhMzs...FcAhw/files/0")
{ "data": "Hello " }
> ipfs.resolve("QmdhMzs...FcAhw/files/1")
{ "data": "World\n" }

> ipfs.resolve("QmdhMzs...FcAhw/files/0/data")
"Hello "
> ipfs.resolve("QmdhMzs...FcAhw/files/1/data")
"World\n"


/*
 * Creating a pseudo file system in a few lines
 */

//  {
//    "data": "content".
//    "files": [
//      <link>,
//      <link>,
//      <link>,
//      ...
//    ]
//  }
function catFile(link) {
  var obj = ipfs.resolve(link)
  var out = obj.data || ""

  for (var file of (obj.files || [])) {
    out += catFile(file)
  }

  return out
}

> catFile("QmUUuaD...Z88Bg")
"Hello "
> catFile("QmSVuc2...ydAHV")
"World\n"
> catFile("QmdhMzs...FcAhw")
"Hello World\n"