EASEE-gas, the European Association for the Streamlining of Energy Exchange – gas, published the Common Business Practice (CBP) document 2017-001/01 on Message Transmission Protocol for Document Exchange.

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.

ENTSOG publishes presentations on its work and activities of its members on data exchange, in particular production use of AS4.  Case studies include EGSSIS (Belgium), ENI (Italy), Gaz System (Poland) GTS (Netherlands), SNAM (SNAM) using AS4 products from Mendelson, Software AG and Tibco.