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.
PigeonReader is the Web mail client of the PigeonAir project, a solution for easily building clustered, scalable, and modular email services. PigeonReader is completely UTF-8 compliant, allowing any charset to be used. It is based on XML, which allows skins and themes to be easily written using the XSLT language. It was written to be easily used in a cluster of Web servers, where multiple and different domains are to be managed transparently to the end user, possibly with different skins, features, and configurations.
PigeonAdmin is the mail administration interface of the PigeonAir project, a solution for easily building clustered, scalable, and modular email services. PigeonAdmin allows many virtual domains of the mail server to be easily managed using a simple Web interface. It allows every domain to have a different configuration than any other. It also allows domain administrators to choose which configurations to force on their own users or which parameters the users will be able to configure and modify by themselves.
Ganglia is a scalable distributed monitoring system for high-performance computing systems such as clusters and grids. It is based on a hierarchical design targeted at federations of clusters. Ganglia is currently in use on over 500 clusters around the world and has scaled to handle clusters with 2000 nodes.
BIE (Business Integration Engine) is an open source integration system that makes it easy for organizations to exchange data with external trading partners regardless of their native applications. It competes in the same space as applications like Microsoft BizTalk except that it is truly cross-platform since it written in Java.
Clusters and server farms often have many nodes and very little hardware support for locating and diagnosing problems, especially if the problem involves the network interface. Helpme is a small stand-alone program that allows a node to use the standard PC speaker, both to signal that a problem has been detected and to render arbitrary alphanumeric text using either Morse code or the NATO phonetic alphabet. The input syntax allows repeating messages and more.