Linux kernel (OS) powered DDG-1000 Zumwalt Class Destroyer built by US Navy
Now what is linux, it is just an Operating System which is used worldwide. Linux for a common man would mean something used in different devices basically for research purposes in NASA, in particle accelerators, also used by Scientists for their studies eg Antartic. Linux is also a vital tool in automobile industry as in car manufacture and also being used by Engineers to build humanoid robots, by security researcher or hackers. Linux is preferred due to its basic properties of being flexible, reliable system and safe. US Navy is now using the Linux Kernel to built their most powerful DDG-1000 Zumawat Class Destroyer.
Certain features of Zumwalt : It has an unique structure which matches with the Space ship and due to this shape it would appear as a small fishing vessel on the enemy radar which gives it the stealth capability; however the actual size of this destroyer is equivalent to 3 USS Constitutions. It also has an Integrated Power system which means it can provide electricity to the weapons basically, which might be used for railguns and the free electron lasers. It would hold the capacity of 58 MW of reserve power as per average battle condition. It has total ship computing environment. Easy access to data, this will give an upper hand to sailors as data will be accessible to sailors at any time and anywhere. It also has an adaptable launcher which would take care of any threat and any missile. Zumwalt carries 16 pre assembled IBM blade servers.
This ship only needs 150 sailors. On a ship with Windows they would need 158 tech's just to keep the OS from crashing.