GraphicsMagick is a robust collection of tools and libraries which support reading, writing, and manipulating an image in over 90 major formats including popular formats like DPX, DICOM, BMP, GIF, JPEG, JPEG-2000, PDF, PNG, PNM, SVG, and TIFF. A high-quality 2D renderer is included, which provides a subset of SVG capabilities. C, C++, Perl, Tcl, and Ruby are supported. Originally based on ImageMagick, GraphicsMagick focuses on performance, minimizing bugs, and providing stable APIs and ABIs. It runs on all modern variants of Unix, Windows, and Mac OS X.
BRL-CAD is a powerful constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing support for rendering and geometric analysis, path-tracing for realistic image synthesis, network distributed framebuffer support, and image and signal-processing tools.
The Model Railroad System is a software package that can help you run your railroad. It allows you to operate your layout, from running trains to working your signals and switches. It has support for a network of Bruce Chubb CMR/I USIC, SUSIC, and/or SMINI nodes, and/or a network of Lenz's XPressNet DCC nodes. Azatrax USB-connected Model Railroad Detectors are supported. Software to create switch lists for freight car forwarding and create timetables for your railroad are included. There is software to help with photographing your trains, and to compute the correct value for those pesky dropping resistors for LEDs and/or incandescent lamps.
Metakit is a small, portable database library using a hybrid relational / hierarchical data model with a column-wise internal storage format. For C++, include a single header file and 125 kb DLL or statically link directly. Ideal for desktops, embedded systems, smartphones, and PDAs. Bindings for Python and Tcl. A very mature, stable code base.
din is a software musical instrument and audio synthesizer. Bezier curves are used to draw and sculpt waveforms, create gating and modulation (FM and AM) patterns, and create delay feedback and volume patterns. You can also create an unlimited number of drones and sculpt their waveforms. It uses JACK to output audio, and supports MIDI, OSC and IRC bot for input. din can be extended and customized with Tcl scripts.
Tk Drag and Drop is an extension for Tcl/Tk to add native drag and drop capabilities to the Tk toolkit. It is designed for Tk versions 8.3.3 and higher. Native drag and drop are supported under Microsoft Windows (XP, Vista, 7), Mac OS X Leopard (Cocoa framework), and Linux (XDND, drag support missing).