From Egon Willighagen:
Jmol is an applet and Java based application designed to display various 3D chemical information. Jmol's features include reading a variety of file types and output from quantum chemistry programs, and animation of multi-frame files and computed normal modes from quantum programs. The JmolApplet is a web browser applet that can be integrated into web pages. It is ideal for development of web-based courseware and web-accessible chemical databases. The JmolApplet provides an upgrade path for users of the Chime plug-in.