Jmol is an open-source Java viewer for chemical structures and biomolecules in 3D. It does not require 3D acceleration plugins. Jmol returns a 3D representation of a molecule that may be used as a teaching tool or for research in chemistry and biochemistry. It is free and open source software, written in Java, it runs on Windows, Mac OS X, Linux and Unix systems. There is a standalone application and a development tool kit that can be integrated into other Java applications, such as Bioclipse and Taverna.