AS4

webMethods supports AS4 ?

Yes. webMethods supports AS4.

Module for AS4 Samples is available on SAG TECHcommunity.

Yes it does support from 9.0

http://techcommunity.softwareag.com/ecosystem/documentation/webmethods/adapters_estandards/eStandards/AS4/9-0_Module_for_AS4_Install_and_Users_Guide.pdf