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.

The European Commission’s Connecting Europe Facility (CEF) Digital programme has launched calls for proposals that aim to further increase the number of implementations of eDelivery based on the AS4 open technical specification, as profiled in the e-SENS Large Scale Pilot. The call is open to users of e-SENS AS4 (public administrations or businesses) but also to providers of AS4 software and services.

In Europe Passenger Name Record (PNR) data exchange is regulated to support prevention, detection, investigation and prosecution of terrorist offences and serious crime.  Annex 2 of the recent  COMMISSION IMPLEMENTING DECISION (EU) 2017/759 of 28 April 2017, which specifies the common protocols and data formats to be used by air carriers when transferring PNR data to Passenger Information Units,  mandates the OASIS AS4 standard as one of three allowed protocols for transmission protocols for the transfer of data.