JHeatChart is a one class Java API for generating heat map charts that was created because very few charting APIs seem to contain the facility to create heat maps. It is not a full featured charting API and cannot be used to other charts. The generated charts are created as Java Image objects, which can be incorporated into a GUI or saved to a file.
FreeCAD is a CAx RAD based on OpenCASCADE, Qt4, and Python. It features some key concepts like Macro recording, Workbenches, and the ability to run as a server. It's also platform-independent. It is is fully scriptable and designed to be easily extensible; only the core functionality is embedded into the core libraries, but all further functionality like support of triangle meshes, CAM, FEM, etc. is implemented in extension modules. Normally, such a module is divided into an 'App' part containing the data structures and algorithms and a 'GUI' containing the graphical representation of data structures, dialogs, workbenches, etc.
Gimp User Filter is a work-alike to Adobe's Filter Factory. It is a generic image processing plug-in that can be used to create new filters for The GIMP without having to go through the process of learning about The GIMP's SDK. Many freely available filters that have been created for Filter Factory can also be used with this plug-in.
LibRaw is a library for reading RAW files obtained from digital photo cameras (CRW/CR2, NEF, RAF, DNG, and others). LibRaw is based on the source codes of the dcraw utility, though some of the drawbacks of dcraw have been eliminated. The users of the library are provided with an API to be used when writing their software programs.
ArahPaint4 is a textile-oriented paint program, mainly for jacquard. It is a simple paint program for raster palette images. It has good tools for drawing images in repetition, support for handling palette images (color reduction, substitution, protected, transparent colors), contour tools, layer support, unlimited undo/redo, support for drawing in aspect ratio (pixels need not be square), a two level grid, and a coordinates display. It is simple, stable, fast, and works well on large images (>8000x8000).
PDFView is a very simple program to view PDF files. on contrast to Preview, the main window will open up maximized, and with the drawer hidden by default. When you toggle the drawer, the main window will resize just enough to show it, and maximize again when you hide it. The zoom level will be as big as possible to make the document fit, making it as easy to read as possible.