OpenRCS

ckleea

https://www.openrcs.com/r01/

The service is provided by several developers of Kamailio SIP server and the main goals are:

    - offer a free SIP address for persons that want to communicate via SIP (including use of TLS for secure communications)
    - run the latest bleeding edge version of Kamailio SIP Server – get immediate access to latest developed features
    - enable world wide developers to get access to a SIP server and play with features related to rich communication services
    - provide more than just simple voice and video, such as:
        - instant messaging, presence, xcap server, websocket for webrtc based communications
    - allow its users to define the routing logic for their communications

Similar to IPTel.org that many of us have been using