ChemDraw - ChemDraw - The Gold Standard for Chemical Structure Drawing and Research Publications.
BKchem - BKChem is a free (as in free software :o) chemical drawing program.
ACD/ChemSketch - ACD/ChemSketch for personal and academic use brings the power of our structure drawing package to your home computer.
GPeriodic - GPeriodic is a periodic table application for Linux.
pymol - PyMOL is a powerful and comprehensive molecular visualization product for rendering and animating...
Gnome Chemistry Utils - The Gnome Chemistry Utils include six chemistry related programs: