SIP UMS is an Unified Messaging Server for the SEMS/IVR. It is an extendable voicemai and IVR platform written in Perl. It includes a web based adminstration tool, voice prompts (in english) and sample scripts that will work with SEMS/IVR.
Lwazi is a robust telephony platform aiming to facilitate speedy development of experimental applications without sacrificing power by combining Asterisk with the MobilIVR Python interface bundled into a single build with a unified control interface.
PloneSkype takes communication on the plone platform beyond the asynchronous mode of email, discussion boards and blogs. PloneSkype allows the Plone portal members to communicate with other portal members via Skype.