The HefeWeizen project is an ebXML messaging (ebMS) system. This system supports the OASIS ebXML messaging version 2.0 and OASIS ebXML Collaboration Protocol Agreements (CPA's) version 2.0 specifications. Its features include: (1) ebMS 2.0 support (Reliable messaging, XML digital signature, XML encryption, HTTP and HTTP(s) support -- server and client authentication, SMTP [in planning stage]; (2) ebCPPA 2.0 - Configuration of trading partners via ebXML CPAs. Requirements are [i] Ruby Programming Language and [ii] Linux/Unix (uses libxml2, libxmlsec1 C libraries).