I am looking for specific OS made just for game networking

Few montsh ago I found about some product and I totally forgot its name, it may have been named something like gameos or with letters OS at the end (OS standing for Operating System) I belive it was possible to use it with unity3d.

I tried googling after it today but nothing comes up. This product if I recall it correctly was OS (operating system) that has been optimized and specially addapted to support large number of players.

Does anyone know the name of this thing so I can look it up again, I tried searching here on forum but its not mentioned and google gives me nothing since I cant remeber the name.

Thanks.