Jmol!

Avogadro is a free, fantastically easy to use molecule editor.

PyMOL is a powerful and comprehensive molecular visualization product for rendering and animating 3D molecular structures.

RasMol is a computer program written for molecular graphics visualization intended and used primarily for the depiction and exploration of biological macromolecule structures, such as those found in the Protein Data Bank. It was originally developed by Roger Sayle in the early 90s.Historically, it was an important tool for molecular biologists since the extremely optimized program allowed the software to run on (then) modestly powerful personal computers. Before RasMol, visualization software ran on graphics workstations that, due to their expense, were less accessible to scholars. RasMol has become an important educational tool as well as continuing to be an important tool for research in structural biology.RasMol has a complex version history. Starting with the series of 2.7 versions, RasMol is licensed under a dual license (GPL or custom license RASLIC).RasMol includes a language (for selecting certain protein chains, or changing colors etc.). Jmol and Sirius has incorporated the RasMol scripting language into its commands.Protein Databank (PDB) files can be downloaded for visualization from members of the Worldwide Protein Data Bank (wwPDB). These have been uploaded by researchers who have characterized the structure of molecules usually by X-ray crystallography, NMR spectroscopy or electron microscopy. »

Calistry is an online Chemistry Calculator. Till date Calistry contains 70+ calculators in the field of Chemistry. Everything in the website is entirely free to use. Other than calculators, Calistry also provides online molecular viewers that visualizes coordinate file of leading molecular dynamic pakages.

Ghemical is computational chemistry package, which is licensed under GNU GPL . The ghemical authors are listed here .

RasTop is a molecular visualization software adapted from the program RasMol, which was initially developed by Roger Sayle. RasTop is particularly adapted for educational purposes and for the rapid analysis of macromolecules at the bench. RasTop wraps a user-friendly graphical interface around the "RasMol molecular engine". There is no need to type on the command line; each command in the menu generates its own script. Through an extended menu and a command panel, users can manipulate numerous molecules rapidly and learn about them. Work sessions are saved in script format and are fully regenerated with a simple mouse click. »

UCSF Chimera is a highly extensible program for interactive visualization and analysis of molecular structures and related data