BKchem is a free chemical drawing program.
Some of the features, you can expect:
* Drawing (bond-by-bond drawing; templates for common rings; expanding of common-groups; draws radicals, charges, arrows; color support ...)
* Editing (unlimited undo and redo capabilities; aligning; scaling; rotation (2D, 3D) ...)
* Export/Import (fully supported SVG-, OpenOffice.org-Draw-, EPS-export; basic support for CML1 and CML2 import and export)