NotORM - http://www.notorm.com/
NotORM is a PHP library for simple working with data in the database. The most interesting feature is a very easy work with table relationships. The overall performance is also very important and NotORM can actually run faster than a native driver.
Requirements:
PHP 5.1+
any database supported by PDO (tested with MySQL, SQLite, PostgreSQL, MS SQL, Oracle)
Usage:
<?php
include "NotORM.php";
$connection = new PDO("mysql:dbname=software");
$software = new NotORM($connection);
foreach ($software->application()->order("title") as $application) { // get all applications ordered by title
 echo "$application[title]\n"; // print application title
 echo $application->author["name"] . "\n"; // print name of the application author
 foreach ($application->application_tag() as $application_tag) { // get all tags of $application
 echo $application_tag->tag["name"] . "\n"; // print the tag name
 }
}
?>