JChemPaint

JChemPaint is a Java program for drawing 2D chemical structures. It is open source and free software. Since it is written on Java, it runs on any computing platform and operating system for which a Java Virtual Machine has been implemented (like Linux, Windows, etc). If your system does not have Java Virtual Machine, you can get it here

Features:

- Drawing and deletion of single, double, triple and stereo bonds

- Colouring of atom types, and other rendering settings

- Editing of atomic charges, isotopes and hydrogen count.

- Loading and saving of structures in Chemical Markup Language (CML) and as MDL MOL files and SDF files (loading only).

- Automated Structure Layout, also known as Structure Diagram Generation.

- Loading structures from the Internet using CAS or NSC number.

- Normalization of structures, currently limited to aromaticity detection.

- Saving bitmap pictures of the structures.

- Saving structures as graphics (PNG, BMP, Scalable Vector Graphics (SVG)).

- Postscript printing

- Translated into several languages: Dutch, French, German, Polish, Portuguese and Spanish.

You can get it here :)

Source: SourceForge