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.
Social Networks Visualizer (SocNetV) is a flexible and user-friendly tool for the analysis and visualization of Social Networks. It lets you construct mathematical graphs with a few clicks on a virtual canvas, load networks of various formats (GraphViz, GraphML, Adjacency, Pajek, UCINET, etc), or create a network by crawling all links in a Web page. The application can compute basic network properties, such as density, diameter, and distances (shortest path lengths), as well as more advanced structural statistics, such as node and network centralities (i.e. closeness, betweenness, graph), clustering coefficient, etc.
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.
Veusz is a scientific plotting package, designed to create publication-ready Postscript, PDF, or SVG output. It features an easy to use graphical interface as well as a command line interface and can be scripted or embedded in Python scripts. Graphs are constructed in a modular fashion from separate components. Datasets can be interactively modified or created from within the program.
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.