A few more details about the vert.x module:
This release includes support for building transactional Vert.x applications. The sub-project has been contributed by Mark Little and builds on ideas from the Software Transactional Memory (STM) and Actors communities. Traditional ACID transactions work well in some situations and not well in others, with durability and atomicity often being the biggest culprits. STM implementations often trade off durability and, where multiple STM objects are involved in the same transaction, atomicity (all or nothing). The benefits of using STM with Actors include a nice programming model for defining scopes of work and scopes of isolation, giving developers the ability to programmatically abort transactions if something in their application fails as well as being able to share state between threads in the same process.