GTKExtra is a useful set of widgets for creating GUIs for the X Window System using GTK+. It is written in C and includes the following widgets: GtkSheet, GtkPlot, GtkPlotCanvas, GtkItemEntry, GtkComboBox, GtkColorCombo, GtkBorderCombo, GtkFontCombo, GtkDirTree, GtkIconList, GtkFileList, GtkIconFileSelection, and GtkCheckItem.
GtkGLMaterialDialogis a GTK+ dialog that can be used to edit 3D-object material properties. It is based on the material properties of OpenGL with diffuse, ambient, specular, emissive colors (RGBA), and a specular coefficient (shininess). The material is previewed by rendering a lit OpenGL sphere in a gtkglarea widget.
The GNU Triangulated Surface Library (GTS) provides a set of useful functions to deal with 3D surfaces meshed with interconnected triangles. It features metric operations (area, volume, curvature, etc.), 2D Delaunay and constrained Delaunay triangulations, robust geometric predicates and set operations on surfaces (union, intersection, etc.), surface refinement and coarsening (multiresolution models), and bounding-boxes trees for collision/intersection detection.
ViewDog is a viewer for nurbs functions, polygonal geometry, and to some degree for iso surfaces of functions over a 3D domain (via marching cube). It also can be used as a graphical frontend for a number of interpolation and approximation algorithms contained in a seperate library (GUL). Import and export via Alias Wavefront 3.0 OBJ files is possible, so it can be used simply as a viewer for OBJ files, too.
Gumshoe is a program that connects to multiple file sharing services, allowing one to search and download from any of them simultaneously with a consistent interface. Currently only Napster and Gnutella are supported. A plugin system makes it easy to add more. A console UI is implemented, graphical and possibly HTML/HTTP interfaces will come later.
HL7lib is a project that will provide a free, correct implementation of Health Level 7 functions. Health Level 7 is commonly used in large hospitals to send patient information among computer systems from different vendors. Since there is no reference implementation of HL7 many of these vendor systems vary widely in their interpretation of HL7.