GNU TeXmacs is a free wysiwyw (what you see is what you want) editing platform with special features for scientists. The software aims to provide a unified and user friendly framework for editing structured documents with different types of content: text, mathematics, graphics, interactive content. TeXmacs can also be used as an interface to many external systems for computer algebra, numerical analysis, and statistics. New presentation styles can be written by the user and new features can be added to the editor using Scheme.
Net-Fu is a DHTML implementation of the classic GIMP NET-FU interface. It uses the GNU Image Manipulation Program and Xvfb to produce a wide variety of royalty-free custom and semi-custom graphics, logos, and clip art of various sorts. You simply select a style of logo from such choices as "neon", "chrome", and "crystal", specify parameters such as text string, typeface, size, and colors, and your logo is returned without further ado.