Holodeck B2B is an open source implementation of ebMS3/AS4. It's fast, lightweight, easy to install and very flexible. 

In the latest release of the popular open source AS4 MSH the modular architecture of Holodeck B2B is taken a step further - making it even more flexible. 
A P-Mode validation function is added, to separate validation from internal & external storage. Using the API of this module you can choose your own method of adding and storing P-Modes. It also lets you apply domain specific guidelines to P-Modes.