APEX

This memo describes the APEX presence service, addressed as the well-

known endpoint 'apex=presence'. The presence service is used to

manage presence information for APEX endpoints.

This memo describes APEX, an extensible, asynchronous message

relaying service for application layer programs.

This memo describes the APEX access service, addressed as the well-

known endpoint 'apex=access'. The access service is used to control

use of both the APEX 'relaying mesh' and other APEX services.

APEX, at its core, provides a best-effort application-layer datagram

service. Options are used to alter the semantics of the core

service. This memo defines various options to change the default

behavior of APEX's 'relaying mesh'.