I got a tweet from someone asking how I did it, and I said that maybe I would turn it into a product to sell, but I would feel guilty if I did that. It's so easy to do, I would feel like a real jerk to charge for this. I present to you, for free, how to put the Joomla Article Index into a module position.

How easy is it to put the Joomla article index into a module position? It's easier than you think. With one of my free plugins, it's even easier - or you can use a more efficient (but more difficult) method.

You need to download my HeadTag plugin - don't worry, it's one of my free extensions. (Or #2)
1. Enable and configure the plugin, setting "Process Content Tags" to "Yes"
(If not #1) You could add this javascript to your template. This is template specific configuration, so no guidance. Sorry.
Create a new "Custom" module.
1. Assign it to whatever module position you want the article index to appear
2. Set "Show Title" to "No"
3. Assign it to appear on all pages
4. In the "Options" tab, set "Prepare Content" to "Yes"
5. In the "Advanced" tab, set the "Module Style" to "HTML5" (this is optional, you will probably want to try others depending on your template)
Use the "Toggle Editor" button to view the module content source code, and add the following code:

<div id="mod_article_index">
{headtag:scriptdeclaration}
(function(){
    document.addEventListener('DOMContentLoaded',function(){
        var ai = document.getElementsByClassName('article-index');
        var target = document.getElementById('mod_article_index');
        target.appendChild(ai[0]);
    });
})();
{/headtag}
</div>

And if you want to see a walkthrough - I made a YouTube walkthrough. This is for Joomla 3. I may create a walkthrough to achieve this in Joomla 4/5 - but I'm not certain putting the Joomla article index into a module position is still a desirable goal.

I hope this helps you achieve the same on your website!

Update 12-11-2018: Replaced jQuery code with pure Javascript.

Joomla Techniques

Joomla Article Index in a Module Position