JavaGroups is a Java package for reliable group communication. It consists of 3 parts: The first part is a socket-like API for application development, providing methods for joining and leaving a group, sending multicast messages to members, and receiving notifications when members join/leave/crash. The second part is a protocol stack which implements reliable communication, and can be configured according to the QoS desired. New protocols can easily be added, and existing ones removed/replaced/modified. The third part is a set of building blocks which give the application/protocol programmer high-level abstractions (e.g. DistributedHashtable, derived from java.util.Hashtable, which is similar to Linda/JavaSpaces).
Heartbeat is a full-function high-availability system for Linux and other POSIX-like OSes. It monitors services and restarts them on errors. When managing a cluster (more than 1 machine), it will also monitor the members of the cluster and begin recovery of lost services in less than a second. It runs over serial ports and UDP broadcast/multicast, as well as OpenAIS multicast. It is easily adapted to different interconnect media and protocols. When used in a cluster, it can operate using shared disks, data replication, or no data sharing. Versions starting with 2.0 are comparable to any commercial HA package, providing resource monitoring, larger clusters, and detailed dependency information.
MPICH is a robust and flexible implementation of the MPI (Message Passing Interface). MPI is often used with parallel or distributed computing projects. MPICH is a multi-platform, configurable system (development, execution, libraries, etc) for MPI. It can acheive parallelism using networked machines or using mulitasking on a single machine.
The OpenLDAP Project is a collaborative effort to provide a robust, commercial-grade, fully featured, open source LDAP software suite. The project is managed by a worldwide community of volunteers that use the Internet to communicate, plan, and develop OpenLDAP Software and its related documentation. OpenLDAP Software provides a complete LDAP implementation including server, clients, C SDK, and associated tools.
PVM (Parallel Virtual Machine) is a portable message-passing programming system, designed to link separate host machines to form a ``virtual machine'' which is a single, manageable computing resource. The virtual machine can be composed of hosts of varying types, in physically remote locations. PVM applications can be composed of any number of separate processes, or components, written in a mixture of C, C++ and Fortran. The system is portable to a wide variety of architectures, including workstations, multiprocessors, supercomputers and PCs.
vpopmail (vchkpw) is a collection of programs and a library to automate the creation and maintenance of virtual domain email configurations for qmail installations using either a single UID/GID or any valid UID/GID in /etc/passwd with a home directory. Features are provided in the library for other applications which need to maintain virtual domain email accounts. It supports named or IP-based domains. It works with vqadmin, qmailadmin, vqregister, sqwebmail, and courier-imap. It supports MySQL, Sybase, Oracle, LDAP, and file-based (DJB constant database) authentication. It supports SMTP authentication combined with the qmail-smtp-auth patch. It supports user quotas and roaming users (SMTP relay after POP authentication).