Tsung is a distributed load testing tool. It is protocol-independent and can currently be used to stress HTTP, WebDAV, PostgreSQL, MySQL, LDAP, AMQP, and XMPP/Jabber servers. It simulates user behavior using an XML description file, reports many measurements in real time (statistics can be customized with transactions, and graphics generated using gnuplot). For HTTP, it supports 1.0 and 1.1, has a proxy mode to record sessions, supports GET, POST, PUT, and DELETE methods, cookies, and basic/digest authentication. It also has support for SSL, WebSocket, and BOSH.
Open MPI is a project that originated as the merging of technologies and resources from several other projects (FT- MPI, LA-MPI, LAM/MPI, and PACX-MPI) in order to build the best MPI library available. A completely new MPI-2 compliant implementation, Open MPI offers advantages for system and software vendors, application developers, and computer science researchers. It is easy to use, and runs natively on a wide variety of operating systems, network interconnects, and batch/scheduling systems.
Dpsyco is a automated system to distribute system configurations to several computers. It is written mainly for the Debian distribution but should be portable (without too much difficulties) to other distributions or Unixes as well. It consists of a number of shell scripts to perform the desired actions. With it you can handle users, add ssh-public-keys, patch the system, update things using cfengine, install files (overriding other package files), and more.
C3 Power Tools are a set of Python scripts that ease the use and maintenance of single and multiple clusters. Of the seven core tools, only two are restricted to root use. The C3 tools stand out from similar cluster tools in that they transparently support multiple clusters as easily as a single cluster. These tools are so flexible that they can also be used on groups of workstations not configured as a cluster.
p-run is a utility that runs a program, script, or series of commands on a large number of hosts in parallel. It simplifies management of machines in computer labs. It uses ssh, and supports password and key-based authentication. p-run uses libexpect, and will run in parallel across as many processes as specified. When run on a large number of hosts, its parallel nature significantly speeds up administration.