It's not technically a memory leak though. It's more to do with finding errors in your code that use unexpectedly large quantities of memory. But since everything is being allocated and deallocated correctly, you're not actually leaking any memory (which I guess you could argue, makes the article even more basic).

In any case, you're right that the title is a little misleading, but pedantry aside, it's still a useful resource.

@trebor: yes, just like @laumars mentioned this article talks very little about memory leaks. Ever since PHP 5.3 the Garbage Collector was introduced which took care of the biggest contributor to memory leaks: circular references in objects. This article talks more about reducing high memory usage which can happen in any version of PHP.