converted to es6

.eslintrc.json

@@ -0,0 +1,5 @@
+{
+  "extends": [
+    "standard"
+  ]
+}

app.js

@@ -0,0 +1,35 @@
+// import Utilities from "./utilities.js"
+import WrappedGL from './wrappedgl.js'
+import FluidParticles from './fluidparticles.js'
+
+function concatenateWords (list) {
+  if (list.length === 0) {
+    return ''
+  } else if (list.length === 1) {
+    return "'" + list[0] + "'"
+  } else {
+    var result = ''
+    for (var i = 0; i < list.length; ++i) {
+      result += "'" + list[i] + "'"
+      if (i < list.length - 1) {
+        result += i < list.length - 2 ? ', ' : ' and '
+      }
+    }
+
+    return result
+  }
+}
+
+WrappedGL.checkWebGLSupportWithExtensions(['ANGLE_instanced_arrays', 'WEBGL_depth_texture', 'OES_texture_float', 'OES_texture_float_linear', 'OES_texture_half_float', 'OES_texture_half_float_linear'],
+  function () { // we have webgl
+    document.getElementById('placeholder').outerHTML = document.getElementById('main').innerHTML
+    var fluidBox = new FluidParticles()
+  }, function (hasWebGL, unsupportedExtensions) {
+    document.getElementById('placeholder').outerHTML = document.getElementById('no-support').innerHTML
+    if (!hasWebGL) { // webgl not supported
+      document.getElementById('error').textContent = 'Unfortunately, your browser does not support WebGL'
+    } else {
+      document.getElementById('error').textContent = 'Unfortunately, your browser does not support the ' + concatenateWords(unsupportedExtensions) + ' WebGL extension' + (unsupportedExtensions.length > 1 ? 's.' : '.')
+    }
+  }
+)