db4o is an object database for Java and all .NET environments. Its features include ACID transactions, automatic class schema recognition, query-by-example, a S.O.D.A. object querying API, native queries, LINQ support on .NET, callback methods, memory files, cascade-on-delete, multi-threaded access, and Java Webstart and servlet support.
For users on Linux and Unix, KDE offers a full suite of user workspace applications which allow interaction with these operating systems in a modern, graphical user interface. This includes Plasma Desktop, KDE's innovative and powerful desktop interface. Other workspace applications are included to aid with system configuration, running programs, or interacting with hardware devices. While the fully integrated KDE Workspaces are only available on Linux and Unix, some of these features are available on other platforms. In addition to the workspace, KDE produces a number of key applications such as the Konqueror Web browser, Dolphin file manager, and Kontact, the comprehensive personal information management suite. The list of applications includes many others, including those for education, multimedia, office productivity, networking, games, and much more. Most applications are available on all platforms supported by the KDE Development. KDE also brings to the forefront many innovations for application developers. An entire infrastructure has been designed and implemented to help programmers create robust and comprehensive applications in the most efficient manner, eliminating the complexity and tediousness of creating highly functional applications.
Qt is a comprehensive, object-oriented development framework that enables development of high-performance, cross-platform rich-client and server-side applications. When you implement a program with Qt, you can run it on the X Window System (Unix/X11), Apple Mac OS X, and Microsoft Windows NT/9x/2000/XP by simply compiling the source code for the platform you want. Qt is the basis for the KDE desktop environment, and is also used in numerous commercial applications such as Google Earth, Skype for Linux, and Adobe Photoshop Elements.
PostGIS adds support for geographic objects to the PostgreSQL object-relational database. In effect, PostGIS "spatially enables" the PostgreSQL server, allowing it to be used as a backend spatial database for geographic information systems (GIS), much like ESRI's SDE or Oracle's Spatial extension.
Social Networks Visualizer (SocNetV) is a flexible and user-friendly tool for the analysis and visualization of Social Networks. It lets you construct mathematical graphs with a few clicks on a virtual canvas, load networks of various formats (GraphViz, GraphML, Adjacency, Pajek, UCINET, etc), or create a network by crawling all links in a Web page. The application can compute basic network properties, such as density, diameter, and distances (shortest path lengths), as well as more advanced structural statistics, such as node and network centralities (i.e. closeness, betweenness, graph), clustering coefficient, etc.
aubio is a library for audio labelling. Features include onset detection, silence detection, beat tracking, and pitch detection. The goal of this project is to provide automatic labelling features to other audio software projects. Functions can be used offline in sound editors and software samplers, or online in audio effects and virtual instruments.
ctunnel is a program for tunneling and proxying TCP or UDP connections via a cryptographic tunnel. ctunnel can be used to secure any existing TCP or UDP based protocol, such as HTTP, Telnet, FTP, RSH, MySQL, VNC, DNS, XDMCP, NFS, etc. You can also chain or bounce connections to any number of intermediary hosts.
CloudVPN is a secure decentralized mesh networking tool. It allows applications to use it as a mesh transport layer for packet routing, easily creating mesh ethernet VPN, secured audio/video broadcasting or communication channels, etc. It can create secured networks with special or weird topologies, so it's very easy to create connection schemes with clustered/decentralized servers, topologies with better throughput, ring-like topologies for failover, long-line for passing through many routes, or tree topology for optimizing inter-server bandwidth needs.