SimpleDB/dev is a local instance of Amazon's SimpleDB. It runs as a server on your local machine and replicates the SimpleDB REST API as specified in Amazon's technical documentation. It implements every SimpleDB query-action and includes a large suite of tests, created from the query examples provided by Amazon.
Dhcpy6d is an open source server for DHCPv6, the DHCP protocol for IPv6 clients. Its development is driven by the need to be able to use the existing IPv4 infrastructure in coexistence with IPv6.
Djigzo is an email server (MTA) that encrypts and decrypts your incoming and outgoing email. Because Djigzo serves as a general SMTP email server, it is compatible with any existing email infrastructure and can easily be placed before or after existing email servers.
(commercial) EtherPage is client/server based product for delivering messages from computers to wireless messaging services such as alphanumeric and numeric pagers.
in.jabberd is a Unix inetd daemon that implements a minimal Jabber server. It uses a simple, single configuration file for usernames/passwords and supports plain text and SHA-1 digest authentication. It handles basic presence information, chat messaging, and buddy rosters, but little else. It is written in pure C, is portable, and uses less than 100Kb RAM per process while running. It is particularly useful for embedded devices with limited resources, such as the Linksys NSLU2.
The Jabber Extensible Communications Platform (Jabber XCP) is more than real-time, person-to-person communications. It is a highly programmable presence and messaging framework, uniquely capable of bridging applications, networks, devices, multi-media, and protocols.
jabberd14 is the latest version of the original implementation of the jabberd server. While not supporting some of the more advanced features of the Jabber protocols, it is stable, reliable and well tested.
jabberd 2 is the next generation of the jabberd server. It has been rewritten from the ground up to be scalable, architecturally sound, and to support the latest protocol extensions coming out of the JSF.
Lopo's Talker OS Star
Lopo's Talker OS Star is a telnet-based chat server (talker) written in C for communicating with users in real time.
Mandriva Directory Server
MDS (Mandriva Directory Server), along with the Mandriva Management Console (MMC), is a powerful system that allows developers, system administrators, and other software vendors to manage users, groups, and their associated policies in both OpenLDAP server and Fedora Directory Server which allows multi-master replication. Its highly ergonomic interface design makes it very easy to use, and delegation of administration enables medium size organization to adopt MDS.
(commercial) Icewarp Server is a secure enterprise instant messaging solution that will improve the speed of corporate communications while achieving a rapid return on investment.
mlmmjadmd is a TCP based server that allows clients to remotely administrate an mlmmj installation. Currently, almost all mlmmj tunables and actions are supported.
n2 is a client/server system for transmitting forensic snapshots from a number of hosts to a receiver node. This receiver collects statistics and is able to present an overview of the current and historical situation on a server.
nassh-relay implements a relay server used with the Secure Shell (hterm) plugin for the Chromium Web browser.
Open DHCP Server
Open DHCP Server is a multi-subnet DHCP server. It supports both dynamic and static leases. It supports multiple domains. It supports relay agents. It supports BOOTP and PXEBOOT. It has user-defined options. Options can be global, range-specific, and client-specific. DHCP ranges can be filtered by MAC address ranges.
OPeNDAP is a client/server system for making local data accessible to remote locations without regard to the local or remote storage format, architecture, or environment.
Openfire (formerly Wildfire) is a real-time collaboration (RTC) server. It uses the only widely adopted open protocol for instant messaging, XMPP (also called Jabber). Openfire is incredibly easy to setup and administer, but offers rock-solid security and performance.
openICEM is a high scalable server software, entirely written in python, aimed to provide a Certified eMail Service as specified by Italian Law DPR.
OpenL2TP is an L2TP client/server written specifically for Linux. It has been designed for use as an enterprise L2TP VPN server or for use in commercial, Linux-based, embedded networking products. It consists of a daemon, openl2tpd, which handles the L2TP control protocol exchanges for all tunnels and sessions, a plugin for pppd to allow its PPP connections to run over L2TP sessions, a Linux kernel driver for efficient datapath, and a command line application for management.
OpenSIPS is a mature implementation of a SIP server/proxy. It is more than a SIP proxy/router, as it includes application-level functionalities. OpenSIPS, as a SIP server, can server as the core component of any SIP-based VoIP solution.
Paranoid TelnetD (ptelnetd) is a telnet server intended for use with legacy or embedded systems (such as hand-held scanners used in warehouses) that communicate with a backend host via telnet.
pppd-sql is a plugin for the Point-to-Point server (pppd) on Linux and Solaris that adds an authentication backend using a MySQL or PostgreSQL database for the Challenge Handshake Authentication Protocol (CHAP) and Password Authentication Protocol (PAP). It supports MS-CHAPv1 and MS-CHAPv2 too. The IPCP negotiation after authentication handshake is also supported. pppd-sql supports a flexible configuration scheme, has built-in failover functionality (no load-balancing), and comes with easy and handy documentation.
Prosody is a server for Jabber/XMPP written in Lua. It aims to be easy to use and light on resources.
psyced is a scalable distributed multi-protocol chat and messaging server solution released as open source. Very powerful but not bloated and not too hard to get into.
RCDevs OpenOTP Radius Bridge
RCDevs OpenOTP Radius Bridge provides a RADIUS RFC-2865 (Remote Authentication Dial-in User Service) API for the OpenOTP Authentication Server.
remotecores is a client/server application used to watch a specific directory on Linux for core files and transfer them to a remote server for collection.
Resara Server is an Active Directory compatible open source server for small businesses designed around Samba 4.
Restund is a modular and flexible STUN and TURN Server, with IPv4 and IPv6 support.
SEMS is a media and application server for SIP based VoIP services. It shows good performance doing basic services like announcements and conference for combination with external application servers.
shrewd is a lightweight and simple Internet Gopher server. It supports IPv4/IPv6 and runs on Unix-like systems (Developed on OpenBSD/i386, tested on NetBSD, FreeBSD and Linux on i386).
SMRadius is a high performance pre-forked RADIUS AAA server. It features a highly configurable backend engine supporting flexible data specifications, traffic and time-based capping, topups, and account validity periods.
SockThread is an implementation of multi-threaded sockets. It is has a built-in echo server for telnet connections.
Stunner is an RFC 3489 STUN server and client for Unix and Unix-line operating systems. It aims to adhere closely to the RFC. The STUN protocol is used to help clients who are located behind network-address translating (NAT) routers determine the sort of NAT being used. It is commonly used as part of Voice-over-IP (VoIP) systems.
sxmppd is a server for the XMPP (Jabber) chat protocol.
Tigase Server is a lightweight and scalable Jabber/XMPP server. No third party libraries are needed. For services with very high load and a huge number of users, it can be deployed on as many machines as needed.
vmodemd is a telnet server designed to run old DOS BBS systems and door games. vmodemd listens for incoming TCP connections on a defined port, does a minimal telnet handshake if needed, and then start to proxy all data to a PTY which is bound to a dosemu virtual serial port.
WACS (pronounced "wax") is a full Comet server that is extremely tiny, fast, and permits you to serve push requests as well as normal Web server requests for simple files.
xbmsd is a file sharing server implementing the Xbox Media Streaming Protocol (XBMSP) supported by the Xbox Media Center (XBMC). The main features of xbmsd besides normal file sharing is mapping files to arbitrary local files or HTTP files/streams, the possibility of generating "synthetic" mplayer configuration files according to file extension and the possibility of specifying file processing filters by file extension.