Chiron FS is a FUSE based filesystem that implements replication at the filesystem level like RAID 1 does at the device level. The replicated filesystem may be of any kind you want; the only requisite is that you mount it. There is no need for special configuration files; the setup is as simple as one mount command (or one line in fstab).
ConMan is a serial console management program designed to support a large number of console devices and simultaneous users. It supports local serial devices, remote terminal servers (via the telnet protocol), IPMI Serial-Over-LAN (via FreeIPMI), Unix domain sockets, and external processes (e.g., using Expect to control connections over telnet, ssh, or IPMI Serial-Over-LAN). Its features include logging (and optionally timestamping) console device output to file, connecting to consoles in monitor (R/O) or interactive (R/W) mode, allowing clients to share or steal console write privileges, and broadcasting client output to multiple consoles.
Crossroads is a daemon running in user space, and features extensive configurability, polling of back ends using wake up calls, status reporting, many algorithms to select the "right" back end for a request (and user-defined algorithms for very special cases), and much more. Crossroads is service-independent: it is usable for any TCP service, such as HTTP(S), SSH, SMTP, RDP, and database connections. In the case of HTTP balancing, Crossroads can provide session stickiness for back end processes that need sessions, but aren't session-aware of other back ends. Crossroads can be run as a stand-alone daemon or via inetd, and features a management Web interface for monitoring and for modification of parameters.
GNU parallel is a shell tool for executing jobs in parallel locally or using remote computers. A job is typically a single command or a small script that has to be run for each of the lines in the input. The typical input is a list of files, a list of hosts, a list of users, a list of URLs, or a list of tables. If you use xargs today you will find GNU parallel very easy to use, as GNU parallel is written to have the same options as xargs. If you write loops in shell, you will find GNU parallel may be able to replace most of the loops and make them run faster by running several jobs in parallel. GNU parallel makes sure output from the commands is the same output as you would get had you run the commands sequentially. This makes it possible to use output from GNU parallel as input for other programs.
Galera wsrep provider is a dlopenable generic replication library which implements the wsrep provider API. It provides very efficient synchronous replication, and multi-master and "parallel applying" capabilities for opaque data buffers. Its primary focus is data consistency. A transaction is either committed on every node, or not at all. It works anywhere TCP works, including on WAN, and can utilize UDP multicast where available. It is used by the MySQL-wsrep patch project to create true multi-master MySQL/InnoDB clusters.
MUNGE (MUNGE Uid 'N' Gid Emporium) is an authentication service for creating and validating credentials. It is designed to be highly scalable for use in an HPC cluster environment. It allows a process to authenticate the UID and GID of another local or remote process within a group of hosts having common users and groups. These hosts form a security realm that is defined by a shared cryptographic key. Clients within this security realm can create and validate credentials without the use of root privileges, reserved ports, or platform-specific methods.
MrTools is a suite of tools for managing large, distributed environments. It can be used to execute scripts on multiple remote hosts without prior installation, copy of a file or directory to multiple hosts as efficiently as possible in a relatively secure way, and collect a copy of a file or directory from multiple hosts.
jrMandel is a command line, parallel Mandelbrot set fractal renderer. It is specially designed to render high-resolution fractal images taking advantage of parallel processing, either by using multiple threads of execution (and thus suitable to run on multi-core processors) or by using a Parallel Virtual Machine (PVM) to distribute the tasks among the nodes of a computer cluster. jrMandel can also render fractals without using any parallelism, in order to compare the efficiency between parallel and non-parallel runs.