Jingle Nodes is a relay auto-discovery service that provides Jingle Relay Type Candidates that can be used in ICE-UDP and also on RAW-UDP Jingle sessions. Relay candidates can provide NAT traversal for users who don't have STUN/TURN Support, but also for users with STUN/TURN support for whom negotiation failed. It is designed to allow you to communicate freely with your friends without being attached to closed service providers like Skype or telecommunications carriers.
sxmppd is a server for the XMPP (Jabber) chat protocol. While other, functional XMPP servers exist, they are not as simple or have many dependencies. It supports user authentication, SSL, roster management, presence updates and subscriptions, messaging (local users), group chat, and file-based server configuration.