hamsterdb Embedded Storage is a database engine written in ANSI C. It supports a B+Tree index structure, uses memory mapped I/O (if available), supports cursors, duplicate keys and can create in-memory databases. Wrappers for C++, .NET, Java and Python are available....

Tuttle OFX is a library to connect and batch operations with OpenFx plugins. It comes with a set of plugins that allows you to batch process on movies and file sequences.

PAL (physics abstraction layer) is a portable C++ physics abstraction API. It provides a unified interface to a number of physics engines (Bullet, ODE, PhysX...).
This enables the use of multiple physics engines within one application. It is not just a simple physics wrapper, but provides an extensible plug-in architecture for the physics system, as well as extended functionality for common simulation components....

This software product is going to be a cross-platform distributed server for various manipulations over large amounts of multimedia data, such as a real-time audio/video transcoding and streaming.

Trojitá is a fast and reliable IMAP e-mail client written using the Qt framework.

The prime goal of GoFigure 2 is the automatic segmentation of nuclei and cell membranes and in temporally tracking them amidst cell division to create lineages.

Kochol Game Engine(KGE) is an object-oriented hardware accelerated 3D Game engine. Easy to use and powerful engine for cutting edge games.

Yzis is a vi/vim engine that is easy to integrate in any graphical application. The goal is to make it easy for people developing an application that requires an editor to integrate yzis. Currently, there is a Qt, ncurses and KDE kpart yzis frontend.

qt twitter client ..,

Purpose
FatRat Library is a free and open source OPC DA (Data Access) Server Toolkit. FatRat Library makes it possible to speed up development OPC DA servers.

OPC compliance
FatRat Library supports:

IOPCCommon
IOPCServer
IConnectionPointContainer
IOPCItemProperties...