The Chemistry Development Kit (CDK) is a scientific, LGPL-ed library for bio- and cheminformatics and computational chemistry written in Java.
The main home page of the CDK is now at: http://cdk.github.io
An editor for small organic molecules, written in C using gtk+. It can read and write SMILES and cml and can save to dia's file format. It is suitable for creating chemical molecule diagrams for lower level chemistry/ochem lab reports.