Libgda is a (relatively small) database access library. It provides a wrapper like ODBC but with more features for accessing several database engines, a general data model for use with CSV or XML files, a metadata extractor that retrieves information about database objects in a common way, and a SQL console application (like mysql, psql or sqlite3 consoles).
Cfengine is a tool for setting up and maintaining BSD and System-5-like operating system optionally attached to a TCP/IP network. You can think of cfengine as a very high level language, much higher level than Perl or shell: a single statement can result in many hundreds of operations being performed on multiple hosts. Cfengine is good at performing a lot of common system administration tasks, and allows you to build on its strengths with your own scripts.
Gorm (Graphic Object Relationship Modeller) is a GNUstep application for building user interfaces and application objects relationships. Its major features include drag-and-drop creation of GUI elements from palettes, run-time loading of additional palettes, direct on-screen manipulation of GUI elements, manipulation and examination of objects via inspectors, and creation of connections between objects using mouse. It is a clone of the former NeXTstep (currently OS X) "Interface Builder" application.
gpsim is a software simulator for Microchip's PIC microcontrollers. It was designed to provide accurate simulation at real-time speeds. Support exists for all three families of PIC's: 12-, 14-, and 16-bit cores. Simulator features like breakpoints (both execution and memory), trace, symbolic debugging, etc. are all supported. Additonally, simulated stimuli like square waves and analog signals are supported or, if you want, you can create your own dynamically loadable modules (like a 7-segment display). gpsim has both a GTK-based GUI and a readline-based CLI.
KDevelop is an integrated development environment which makes the creation and development of applications an easy task even for beginners. Highlights of the current release are: an application wizard for easy creation of KDE 4, Qt4, GNOME, and terminal C/C++ projects, full project management, a syntax-highlighting editor, code completion, an integrated dialog editor for the Qt/KDE GUI libraries, an internal debugger, a full-featured class browser with class tools, CVS and SVN support, an integrated HTML-based help system offering manuals and class-references, and extensive search mechanisms to browse sources and documentation.
KernelDriver automates your Windows 2000/NT, Windows Me/98/95 and Linux device driver development by providing you with powerful tools for hardware debugging, driver code generation, and driver debugging. KernelDriver supports PCI / USB / ISA and EISA drivers. KernelDriver for Windows and Linux includes the powerful Driver Wizard. Using the Driver Wizard you can graphically debug your hardware by "peeking" and "poking" at it without writing a single line of code. After your hardware is diagnosed, use the Driver Wizard to generate a complete kernel mode device driver which will drive your hardware.
leJOS is a Java-based replacement firmware (OS) for LEGO Mindstorms programmable bricks, including RCX and NXT. It supports threads, exceptions, synchronization, floating point arithmetic, strings, and so on, but there is no garbage collection yet. It is also designed to be portable to other small devices.