Bitcoin is a peer-to-peer electronic cash system that is completely decentralized, without the need for a central server or trusted parties. Users hold the crypto keys to their own money and transact directly with each other, with the help of a P2P network to check for double-spending.
phpMyFAQ is a multilingual, completely database-driven FAQ system. It support various database systems and it also offers a content management system with a WYSIWYG editor, an image manager, flexible multi-group and multi-user support, a news system, user tracking, language modules, templates, PDF support, a backup system, Active Directory support, and an easy to use installation script.
Tiki Wiki CMS Groupware is a full-featured, Web-based, multilingual, tightly integrated, all-in-one wiki, CMS, and groupware. Tiki can be used to create all kinds of Web applications, sites, portals, knowledge bases, intranets, and extranets. Tiki offers a very large number of features "out-of-the-box". It is highly configurable and modular. All features are optional and administered via a Web-based interface. Major features include a robust wiki engine, news articles, discussion forums, newsletters, blogs, file and image galleries, bug and issue trackers, a link directory, polls/surveys and quizzes, FAQs, a banner management system, calendar, maps, mobile access, RSS feeds, a category system, tags, an advanced themeing engine (Smarty), spreadsheet, live support, shoutbox, inter-user messaging, menu generator, advanced permission system for users and groups, internal search engine, external authentication support, and more. It was formerly named TikiWiki.
Thunderbird is a total redesign of the Mozilla mail component to produce a cross-platform, stand-alone mail application using the XUL user interface language. It has many new features, among them the ability to customize your toolbars the way you want them. a new look and feel with a large number of downloadable themes which alter the appearance of the client, and the ability to add UI extensions.
LimeSurvey (formerly PHPSurveyor) is a Web application that interacts with MySQL, MSSQL, or Postgres to develop surveys, publish surveys, and collect responses to surveys. Once a survey has been created, data can be inserted into the survey either by a "pretty" public screen which presents each question one at a time, or by a quick and nasty data entry screen. It includes the capacity to generate individualized "tokens", so that invitations can be issued to participants. It also has the capacity to set conditions on whether questions will display (branching), numerous question types, and a basic statistics function.