The GIMP IFF plugin allows you to load and save .iff/.lbm pictures. It supports 1-8, 24bit planar images, 3-8bit HAM and EHB images, 12/24bit Imagine/TurboSilver pictures and DPaint IIe output. It saves indexed, grayscale and 24bit. Compression is supported, as well as transparency (masks) in most cases.
Gutenprint (formerly Gimp-Print) is a collection of printer drivers for Unix/Linux that currently supports over 1400 printers. It emphasizes quality and flexibility, offering a wide variety of options to meet most printing needs. It includes a CUPS driver, an IJS-based Ghostscript driver, Foomatic data, an enhanced Print plugin for The GIMP, and other printer maintenance utilities. It can be used equally well for fast printing of text or critical printing of high quality graphics and photographs.
Ginko is a simple "wish" application, which provides a GUI front end allowing a flatbed scanner and a Hewlett-Packard LaserJet printer to be used as a copier. It uses the SANE package to drive the scanner, the NETPBM package to convert scans to PostScript or PCL, and whatever version of lpr you have installed to do the printing.
GLE is a library package of C functions that draw extruded surfaces, including surfaces of revolution, sweeps, tubes, polycones, polycylinders and helicoids. Generically, the extruded surface is specified with a 2D polyline that is extruded along a 3D path. A local coordinate system allows for additional flexibility in the primitives drawn. Extrusions may be texture mapped in a variety of ways. The GLE library generates 3D triangle coordinates, lighting normal vectors and texture coordinates as output. GLE uses the GL or OpenGL API's to perform the actual rendering.
Glt is a library of C++ classes and routines for programming interactive 3D graphics with OpenGL. The aim of Glt is to augment the OpenGL API with convenient mechanisms for manipulating the OpenGL state machine. Glt is a work in progress, and by no means covers the entire OpenGL specification. However, it already includes several useful classes and is designed so that additional classes can be added easily. In addition to Glt, the GlutMaster classes provide C++ wrappers for the GLUT API.
Generic Mapping Tools (GMT) is a free, public-domain collection of about 60 UNIX tools that allow users to manipulate (x,y) and (x,y,z) data sets (including filtering, trend fitting, gridding, projecting, etc.) and produce Encapsulated PostScript File (EPS) illustrations ranging from simple x-y plots through contour maps to artificially illuminated surfaces and 3-D perspective views in black and white, gray tone, hachure patterns, and 24-bit color. GMT supports 25 common map projections plus linear, log, and power scaling, and comes with support data such as coastlines, rivers, and political boundaries.