Quantcast File System (QFS) is a high-performance, fault-tolerant, distributed file system developed to support MapReduce processing, or other applications reading and writing large files sequentially.

RetroShare is a Open Source cross-platform, Friend-2-Friend and secure decentralised communication platform.
It lets you to securely chat and share files with your friends and family, using a web-of-trust to authenticate peers and OpenSSL to encrypt all communication.
RetroShare provides filesharing, chat, messages, forums and channels

FlameRobin is a database administration tool for Firebird RDBMS.

HTCondor is a specialized workload management system for compute-intensive jobs. Like other full-featured batch systems, HTCondor provides a job queueing mechanism, scheduling policy, priority scheme, resource monitoring, and resource management. Users submit their serial or parallel jobs to HTCondor, HTCondor places them into a queue, chooses when and where to run the jobs based upon a policy, carefully monitors their progress, and ultimately informs the user upon completion.

Apache Mesos is a cluster manager that provides efficient resource isolation and sharing across distributed applications, or frameworks. It can run Hadoop, MPI, Hypertable, Spark (a new framework for low-latency interactive and iterative jobs), and other applications.

Calls can be made peer-to-peer behind NAT firewalls, and without needing a service provider. GNU SIP Witch does not perform codec operations and thereby enables SIP endpoints to directly peer negotiate call setting and process peer to peer media streaming even when when multiple SIP Witch call nodes at multiple locations are involved. This means GNU SIP Witch operates without introducing additional media latency or offering a central point for media intercept or capture. GNU SIP Witch can be used to build secure and intercept-free telephone systems that can operate over the public Internet.