This article introduces one of the most foundation topics in WordPress development: the server-side software that makes WordPress work. Often referred to as “the stack,” as this article explains the “LAMP stack” that most WordPress sites run on is just an initalism of the software packages of Linux, Apache, MySQL, and PHP. And that stack is just as useful today as it was 15 years ago when WordPress started.

Debates have raged for ages—and still rage—about how to think about code on a WordPress site. Some people are fast-and-loose types who just want it working quickly as possible. For people in a hurry, the Code Snippets plugin is a quick and effective way to build and manage small quick “WordPress hacks.” While I still think file-system access is a better idea for writing WordPress PHP, I can’t deny the quickness of this (or any) PHP code snippets plugin.

This article will take you by the hand and lead you to become a WordPress plugin developer. We’ll analyze when the circumstances call for writing a plugin, where to place your plugin code and some best practices, and give you a taste of a few WordPress concepts regarding plugin development while coding a simple plugin.

In this WordPress tutorial for PHP developers, we’ll look at how to start developing WordPress websites if you’re new to WordPress but already understand PHP.

When it’s time to choose a WordPress theme for your website, you have tons of options. Perhaps the most powerful is to forego the readymade themes on the market and build your own. Building your own theme puts you in complete control when it comes to looks and functionality. It can take your project up to that next level. That’s why today, we’re going to show you how to create a WordPress theme from scratch.

The topics of SQL and database performance optimization are important to a small percentage of WordPress sites. But when they matter, they matter a whole heck of a lot. It is in those situations that the WordPress plugin Query Monitor comes in. Maintained by John Blackbourn, Query Monitor is a great way to see what database queries were run on specific page of your site, and find out what the slow ones are. Once you find that, you’ve still got some work to do—tracking down the problematic query’s source, fixing the code that produced the query, etc—and unfortunately that work is far outside the scope of this little Quick Guide. All that said, let’s cover the basics of how to start to understand what’s going on with the WordPress Query Monitor plugin.

In this text and video Quick Guide, we’ll explain how to register custom taxonomies using the Pods plugin. Using Pods to create custom taxonomies is easy, and doesn’t require writing any PHP code of your own.

Say you have a category page on which you’re asked to display all the posts that belong to that category’s subcategories. So far no sweat – a category page displays by default all its descendant posts, whether they belong directly to that category or any of its subcategories. But here’s the twist: say you have to display them in such a way that the subcategory names are displayed (challenge no. 1), and under each subcategory’s name you have to display all its posts (challenge no. 2).

This text and video Quick Guide covers how to install WP-CLI, the WordPress command line interface.

WordPress’s get_queried_object() function has the distinction of being, I think, the most useful core function in WordPress that I didn’t know about for the longest time.