As Vincent reported in his post “Medical GNOME“, the French company Supersonic Imagine (founded in 2005) just announced its next-generation ultrasound system for breast lesion imaging that will come with mostly Open Source software components.
The new system is called Aixplorer™. According to the message of N. Bruguier in the GNOME Desktop Development List it is based upon a derivative of Ubuntu. Beside GNOME/GTK it utilizes the cairo graphics library and the Cairo Composite Manager for the GUI.

Their customized packages and patches are available via Launchpad.