The VPG tool is an optional graphical user interface (GUI) for VPLG. It allows you to set the file system paths to the other programs and select a PDB file to process. It will then generate the proper command line and execute PLCC for you. It is written in Java.
The VPG program has recently been rewritten from scratch and is currently in alpha state. Here is a screenshot of the new version:
VPG can be used to:
1. Download PDB and DSSP files from remote servers
2. Create Protein ligand graphs (both images and graph files in various text formats)
3. View graph images to examine their structure
There currently is virtually no documentation for it but it is designed to be pretty self-explanatory. Note that VPG makes intensive use of tool tips for guiding the user, so if you need more information on an option, just hover your mouse over it.