K-3D is the free (as in freedom) 3d modeling, animation, and rendering system.
NOTE: FontForge has moved to fontforge.github.io, newer binaries and sources are available at github.com/fontforge. FontForge allows you to edit outline and bitmap fonts. You may create new ones or modify old ones. It is also a format converter and can interconvert between PostScript (ascii & binary Type1, some Type3, some Type0), TrueType, OpenType (Type2), CID, SVG
Sodipodi is general vector illustrating application for Linux/Unix and Windows. It uses W3C SVG as native file and in-memory image format and can do many neat things.
Figurine is a vector graphics editor for X11 that uses the xfig FIG3.2 format.
Linux 2D CAD/CAM
Raph Levien's Spiro package as a library. A mechanism for drawing smooth contours with constant curvature at the spline joins.
A UML class diagram editor written in C++ using Tcl/Tk for the GUI portion. Designed to be easy to maintain and extend.
Meshgen is designed to interactively generate 2D FEM meshes composed of triangular and quadrilateral elements.
Y.A.P.R.M. is a free-as-in-freedom modeller to graphicaly design 3d scenes and generate POV-Ray-files for them. Appart from the basic POV-Ray objects which can be used in CSG operations it supports spline based objects. Furthermore a vast amount of 3d-files can be imported and used with Y.A.P.R.M.
monoGIS will be a complete GIS suite for the Mono platform. The current milestone release includes an internet mapserver, OGC WMS implementation and some tools like spatial format conversion. For other projects using monoGIS see mdwglib and Appomattox.
Exymen aims towards being a universal cross platform multimedia editor. The goal is to have one application capable of editing all kinds of media content, including sound, video, slide presentations and white board content. Exymen has an open generic AP
Magda is Aesthetic Graph Drawing Application.
Varkon.Org is a resource site for users of the Varkon parametric CAD and modeling system. This site is a mirror and archive for the Varkon.Org site. You can find all versions of modules for use with Varkon on this mirror site. See the website for info.
XDraft is a mechanical drawing editor similar to XFig or various Windoze cad programs, but geared towards more precise drawing. XDraft adds input constraints and other features that makes it highly suitable for power users. Also includes dimensioning.
mvComicsMaker (mvCM) is a free, QT-based graphics editor for creating animations in Linux. Working with mvCM, you are able to use bitmapped images together with vector graphics. You can also combine indexed pictures with true color pictures.
A tool for making enhanced typesetting in xfig easy. It is using latex for setting the text.