If you previously read webglfundamentals.org there are some differences that you should be aware of.
On webglfundamentals.org nearly all scripts are stored
<script id="vertexshader" type="not-js">; shader goes here </script>; ... var vertexShaderSource = document.querySelector("#vertexshader").text;
On webgl2fundamentals.org I've switched to using multiline template literals
var vertexShaderSource = ` shader goes here `;
multiline template literals are supported on all WebGL capable browsers except IE11. If you need to target IE11 consider using a transpiler like babel.
I switched all the shaders to GLSL 300 es. I figured What's the point of using WebGL2 if you're not going to use WebGL2 shaders.
Vertex Array Objects are an optional feature on WebGL1 but they are a standard feature of WebGL2. I think they should be used everywhere. In fact I almost think I should go back to webglfundamentals.org and use them everywhere using a polyfill for those few places they are not available. There is arguably zero downside and your code gets easier and more efficient in almost all cases.
I tried to re-structure many samples slightly to show the most common patterns
For example most apps generally set global WebGL state like blending, culling, depth testing in their render loop since those settings often change several time where as on webglfundamentals.org I set them at init time because they only needed to be set once but that's not a common pattern.
I set the viewport in all samples
I left this out in webglfundamentals.org because the samples don't actually need it but it's needed in just about all real world code.
I removed jquery.
Back when I started it was maybe still not common to
<input type="range"> but now it's supported
I made all helper functions have a prefix
var program = createProgramFromScripts(...)
I hope this makes it more clear what those functions are and where to find them.
I'm debating whether or not to change any of the webglfundamentals examples to match. It took a couple of weeks of solid work to edit all the existing examples and articles. I mostly feel within 12 months WebGL1 will be mostly replaced by WebGL2 because all the browsers are on auto update. Firefox and Chrome will ship WebGL2 soon covering a large percentage of users on desktop and Android. If Apple and Microsoft add WebGL2 support to Safari macOS, Safari iOS and Edge respectively then probably the majority of people will be covered and we can all just move on to WebGL2.
Hopefully I'll find time to add more articles. Given the point above, from now on all new articles will be WebGL2 only I think.