GPL vs SonoCalc™ IMT Embedded Linux Software

Hi

It is known that the MicroMaxx system runs embedded Linux.

http://www.sonosite.com/content/view/31/120/

The MicroMaxx system also includes SonoCalc™ IMT, proprietary
edge-detection software that enables clinicians to quickly and easily
measure intima-media thickness of the carotid artery for assessment of
arterial wall disease progression and cardiovascular risk.

http://preview.tinyurl.com/yfwsxo

A Micro$oft version is available too...for a price.
Required: PC running Windows 2000 or XP,(For optimal performance, the
user’s PC should have at least 256MB of RAM and at least a 500mHz
Pentium-class (or equivalent) CPU.)

Is the embedded version under the GNU General Public License (GPL) by
default?

Thanks

.