gElemental is a periodic table viewer derived from GPeriodic that provides detailed information on the chemical elements. It uses the GTK+ toolkit and is available for Linux and other GTK+ platforms. It also provides Python bindings to the data, which is stored in a separate data library.
GenChemLab (General Chemistry Lab Simulator) is a graphical application for simulating several common general chemistry exercises. It is meant to be used to help students prepare for actual lab experience.
Ghemical is a computational chemistry software package with GUIs for both GLUT and GTK+, and some nice 3D-visualization tools. It can do "all atoms" molecular mechanics and dynamics, as well as quantum mechanics (ab initio and semi-empirical) models. It hopefully offers a good framework for a generic freeware molecular modeling tool.
Ghemical-GMS is a specialized version of Ghemical developed for GAMESS. Ghemical-GMS contains an extra set of menus for creating GAMESS input files, and allows for the submission and queuing of GAMESS jobs using the GTK-Gamess program.
Gibbs perfoms Gibbs-ensemble simulations with cavity-biased insertion to determine the densities of coexisting liquid and vapor phases in equilibrium with each other.
Gnome Chemistry Utils
The Gnome Chemistry Utils provide C++ classes and Gtk+-2 widgets related to chemistry. They are used both both in <a href=http://www.nongnu.org/gcrystal/>Gnome Crystal</a> and <a href=http://www.nongnu.org/gchempaint/>GChemPaint</a>.
Gnome Crystal is a lightweight model visualiser for crystal structures.
Gnu Xtal System
The Gnu Xtal System is a package of over sixty crystallographic programs for calculations ranging from the reduction of raw diffraction intensities, to the solution, refinement and publication of crystal structures. These are applicable to X-ray, neutron and electron diffraction analyses, including charge density studies. The package contains interactive graphics tools.
GOLD is a program for calculating the docking modes of small molecules into protein binding sites as part of a virtual screening application. Docking is performed using a genetic algorithm and incorporates full ligand flexibility and partial protein flexibility. The GoldScore and ChemScore scoring functions are available, or a custom scoring function can be implemented. Cavity-bound waters and constraints can be included as part of the docking procedure.
gOpenMol is a graphics interface to the OpenMol set of programs, but can also be used for the analysis and display of molecular dynamics trajectories and the display of molecular orbitals, electron densities and electrostatic potentials from many programs.