GDIS is a GTK based program for the display and manipulation of isolated
molecules and periodic systems. It is in development, but is nonetheless
fairly functional. It has the following features:
   - Support for several file types (CIF, BIOSYM, XYZ, XTL, MARVIN, and GULP)
   - A simple molecular creation and manipulation tool
   - A dialogue for creating starting configurations for molecular dynamics
     simulations
   - Assorted tools for visualization (geometry information, region
     highlighting, etc.)
   - Animation of BIOSYM files

WWW: http://gdis.sourceforge.net/