LoaderOne

A better PHP class file autoloader library than PSR.

Why LoaderOne

PSR Specifications are so badly! Totally can't as a standard even or a suggestion because it too loosely and personalized customization.
For the first reason, Composer is terrible too, it makes the PHP world messing.
Conveniently to using and simply, scientific rules.
Also good performance.

Download the LoaderOne source code floder placed it in your project dir anywhere, commonly at project root dir is ok.

Setting the third-party "Class" lookup paths of the project dir in find_path.php (.e.g: Assume a thrid-party class fully qualified class is \Acme\Log\Writer\File_Writer, and you can place it at "Vendors" or "Library" or whatever else dir, so you need specify for this case.)
Add below code in your entry PHP file, commonly is index.php, and classes can auto loaded.

...


$autoLoader = include_once 'LoaderOne\Autoloader.php';
$autoLoader->setBasePath(`YOUR_PROJECT_ROOT_DIR`);

...

PHP 5.3+

Keep the "Namespace" completely mapping the actual directory's hierarchy.
Keep the "Class" and "Namespace" naming & capitalized same as the located directories name.

FULLY QUALIFIED CLASS	PROJRCT ROOT	FIND_PATH	RESULTING FILE PATH
\Acme\Log\Writer\File_Writer	\var\www\html\atest	Vendors	\var\www\html\atest\Vendors\Acme\Log\Writer\File_Writer.php
\Aura\Web\Response\Status	\var\www\html\atest	Vendors	\var\www\html\atest\Vendors\Aura\Web\Response\Status.php
\Symfony\Core\Request	\var\www\html\atest	Library	\var\www\html\atest\Library\Symfony\Core\Request.php
\Zend\Acl	\var\www\html\atest	Library	\var\www\html\atest\Library\Zend\Acl.php