Echomine Feridian is an easy-to-use Java API that gives you quick and easy access to the XMPP network used in IM services such as Google Talk. The API allows you to communicate with Jabber/XMPP servers for sending and receiving instant messages, presence management, and custom extensions to the XMPP protocol.
weta-dfs is a distributed file system. It is designed to be fail-safe through replications of files, fast and easy to install, platform independent, and to have fast recovery from crashes. It consists of Data Node Servers and one Meta Data Server and a java.io.File-like client API.
Tranche is file storage and dissemination software. Designed and built with scientists and researchers in mind, Tranche can handle very large data sets, is secure and scalable, and all data sets are citable in scientific journals. Features include a fully decentralized architecture, support for very large files, very long-term file persistence/preservation, file immutability/integrity, provenance, encryption, licensing, versioning, and citability.