RedBeanPHP is a simple and easy-to-use ORM, and this module is a lightweight ProcessWire wrapper and/or loader for it.
The main task of the module is loading and setting up RedBeanPHP with database credentials from $config. There are some config settings for defining how RedBeanPHP should behave, and the module also exposes some often-used methods, but that's just about it. For more details (including a rant about why one might prefer separate ORM in some cases), take a look at the README file.
Please note that, for almost all use cases, the data modeling features of ProcessWire are much better choice than a separate database structure of your own, but in those rare cases where that's not the situation, it's good to have options. This module was a side product of one of my own projects, and I thought I might as well share it with you folks.
You can grab the module from GitHub: https://github.com/teppokoivula/RedBeanPHP.