HTTP Adaptation with Open Pluggable Edge Services (OPES). - Alex Rousskov; Martin Stecher (RFC, 2005)

Open Pluggable Edge Services (OPES) SMTP Use Cases. - Martin Stecher; Abbie Barbir (RFC, 2006)

Integrity, Privacy, and Security in Open Pluggable Edge Services (OPES) for SMTP. - Martin Stecher (RFC, 2007)