Avogadro - Avogadro is a free, fantastically easy to use molecule editor.
pymol - PyMOL is a powerful and comprehensive molecular visualization product for rendering and animating...
BKchem - BKChem is a free (as in free software :o) chemical drawing program.
Jmol - Jmol is a free, open source molecule viewer for students, educators, and researchers in chemistry...
Rasmol - RasMol. 96 likes. RasMol is a computer program written for molecular graphics visualization intended and used mainly to depict and explore biological...
ChemDraw - ChemDraw - The Gold Standard for Chemical Structure Drawing and Research Publications.