Molecular visualization programs are available on many platforms. They allow a user to visualize and manipulate molecular structures. PocketMol provides the same functionality on a Pocket PC handheld computer. Using standard protein data bank (pdb) files, the user can move, rotate, and scale a protein to explore its structure and function. The user can choose from a standard backbone view or a simplified view using only alpha carbon atoms. PocketMolGX uses the Microsoft Game API to provide fast animation that is quite smooth. PocketMol is designed as an aid for those wishing to explore or demonstrate protein structures without the availability of a full-size computer