Asymptote is a powerful descriptive 2D and 3D vector graphics language for technical drawing, inspired by MetaPost but with an improved C++-like syntax. It provides for figures the same high-quality level of typesetting that LaTeX does for scientific text. Asymptote is a programming language as opposed to just a graphics program. It can exploit the best features of script (command-driven) and graphical user interface (GUI) methods. High-level graphics commands are implemented in the language itself, allowing them to be easily tailored to specific applications.
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.
QGolf was developed for radio amateurs to clarify the behaviour of a signal on an antenna. It demonstrates the forces that act on a rope if you move one end of it: you can see how waves are reflected, how resonance occurs, and how multiple pulses coexist on the same rope. Various parameters can be updated during the simulation.
Structure101 is a tool to understand, measure, and control software structure. It allows you to see exactly how your high-level components depend on each other and why. You can use it to find out immediately when your architecture is accidentally changed by code-level changes at the coal-face. It can help you control structural complexity, since it can measure the complexity of methods, classes, and packages and warn you when given limits are exceeded. It can also discover the locations of productivity-killing package dependency cycles.
The FOX (Free Objects for Crystallography) program is made for determining crystal structure ab initio from diffraction data (mostly powder diffraction). It is built on an object-oriented crystallographic computing library called ObjCryst++. FOX features a graphical interface, including a 3D OpenGL display of the crystal structure. It provides a versatile description of the crystal structures (such as atoms, molecules, and polyhedra). Special positions and overlapping atoms are automatically handled without any a priori knowledge.
AGM Build is a molecular builder and conformational editor. It can be used for interactive model preparation for molecular dynamics simulations, including association of atom types and partial charges. It features geometry editing, lattice building, building of chain molecules (e.g. proteins), chains with predetermined conformations, and charges and atom types according to selected Force Field.