Gossamer Health is available from SourceForge: http://sourceforge.net/projects/gossamerhealth/
You can download a functioning virtual machine with the Gossamer Health code already set up here:
The sourceforge site may be slow at times. The latest version of the virtual machine can be downloaded directly from https://gossamer.cirg.washington.edu/download
There's a 15 min screen capture demonstration of how to download and get a virtual machine up and running here.
(the cool streaming viewer seems broken, but you can also directly access the video here)
Once the virtual machine ".ova" file is downloaded, it can be installed into the free, VirtualBox application (www.virtualbox.com). VirtualBox runs on Windows, and most other operating systems. Instructions for importing ".ova" files can be found on the VirtualBox website. After importing, be sure to set up networking before starting the virtual machine.
When you connect to your Gossamer virtual machine for the first time through your browser you will see a warning. Just click "Proceed". The warning occurs because we use a self-signed certificate in order to use "HTTPS".