RAA - vapor

Vapor is a persistent Object-Repository for Ruby, providing transparent persistence of interrelated Ruby application objects to a PostgreSQL database. It's goal is to provide developers with an easy-to-use framework for persistence, that is consistent with OO design and does not interfere with the code of classes that are to be persistently stored. Vapor does not require any knowledge about relational databases to be used, so that developers can concentrate on the task of writing their application logic.

Some of Vapor's general design was inspired by the JDO (Java Data Objects) standard.

0.81 mainly fixes documentation errors, that were left uncommitted on my notebook (^^;
0.80 fixes tons of bugs and adds support for object versioning
0.70 adds tupport for transactions (ACID) using optimistic locking