Good PHP ORM Library?

Answer 1

Give a shot to dORM, an object relational mapper for PHP 5. It supports all kinds of relationships (1-to-1), (1-to-many), (many-to-many) and data types. It is completely unobtrusive: no code generation or class extending required. In my opinion it is superior to any ORM out there, Doctrine and Propel included. However, it is still in beta and might change significantly in the next couple months. http://www.getdorm.com

It also has a very small learning curve. The three main methods you will use are:

getClassName('id_here');
$dorm->save($object);
$dorm->delete($object);