Gri is an extensible plotting program designed for scientists. It can draw x-y plots, contour plots, and image plots, and has rudimentary programming capabilities. Output is PostScript. Gri is not mouse driven, nor GUI-based; it is a language. Users regard it as an analogue to the LaTeX document formatting language: users gain considerable power, at the price of a moderate learning curve.
Grok is a library of Java components for performing various natural language tasks. These include several preprocessing tasks, chart parsing, a large categorial grammar for English (induced from the Penn treebank), and some knowledge representation components (basic coreference, salience tracking, etc.). The library also has a companion kit which provides a GUI interface to the components, several of which are implementations of interfaces in the Quipu OpenNLP API.
Groups, Algorithms, and Programming (GAP) is a system for computational discrete algebra with particular emphasis on computational group theory and related areas. It provides a Pascal-like interpreted language, data types for many algebraic objects, a function library, and large libraries of data.
GRPN is a RPN calculator for the X Window system built using the GIMP Toolkit (GTK). GRPN works with real numbers, complex numbers, matrices, and complex matrices. Numbers can be displayed in 4 different radix modes, and complex numbers can be displayed in either Cartesian or polar form, in decimal or engineering notation.
gstar provides a GTK frontend for "starchart", a program written in 1987 by Alan Paeth. The frontend offers a list of pre-defined areas of the sky to chart, plus controls to customize the chart in several ways. Buttons pop up a given postscript chart in gv, or save it to file. Since Paeth's program is freely distributable the source for starchart (along with data files) has been rolled into the gstar package, making it self-contained.
GtkDatabox is a widget for the GTK+ library designed to display large amounts of numerical data quickly and easily. It allows for one or more data sets of thousands of data points (X and Y coordinates) to be displayed and updated in split seconds. It offers the ability to zoom into and out of the data, and to navigate through your data by scrolling. In addition to rulers and a simple coordinate cross, it allows you to add one (or even more) configurable grids like on an oscilloscope. Data may be presented as dots, lines connecting the data, or vertical bars. The widget allows you to easily transform pixel coordinates into data coordinates, thus allowing you to easily create powerful applications for data analysis.
GtkMathView is a GTK widget for rendering MathML documents. It is meant to be a standalone, light-weight component and not a full browser. GTK applications can use the widget as a window for displaying mathematical formulas and doing simple interactions. Among other features, GtkMathView includes support for breaking long mathematical expressions, rendering of stretchy operators, and provides a customizable support for additional fonts.
The GNU Triangulated Surface Library (GTS) provides a set of useful functions to deal with 3D surfaces meshed with interconnected triangles. It features metric operations (area, volume, curvature, etc.), 2D Delaunay and constrained Delaunay triangulations, robust geometric predicates and set operations on surfaces (union, intersection, etc.), surface refinement and coarsening (multiresolution models), and bounding-boxes trees for collision/intersection detection.
ViewDog is a viewer for nurbs functions, polygonal geometry, and to some degree for iso surfaces of functions over a 3D domain (via marching cube). It also can be used as a graphical frontend for a number of interpolation and approximation algorithms contained in a seperate library (GUL). Import and export via Alias Wavefront 3.0 OBJ files is possible, so it can be used simply as a viewer for OBJ files, too.