Com­bat : Spe­cial Oper­a­tions is being devel­oped using GameCore. 

GameCore is an advanced, next-gen game devel­op­ment plat­form that pro­vides bleed­ing edge visu­als com­bined with rapid devel­op­ment. Every­thing you see on this site was cre­ated by 1 per­son — and the sole rea­son for this is GameCore. Of course I’m a lit­tle biased, I’m the CTO of the com­pany, but hey, you’ll be sur­prised with what you can do — give it a try for yourself.

Here’s the lat­est ‘offi­cial trailer’ for GameCore. Some C:SO footage in there even ;}

A few fea­tures that GameCore provides:

• True 64 bit HDR rendering
• Advanced Post-Processing, includ­ing Screen­space Ambi­ent Occlu­sion, Depth of Field and much more
• ‘Cloud-based’ user account man­age­ment, includ­ing Global Leader­boards, Achieve­ments, Stats and Network-enabled save games (Never lose your save games again!)
• Pro­ce­dural con­tent cre­ation, sup­port­ing dense forests & lush jungles
• Dynamic multi-threaded stream­ing sup­port for tex­ture & object management
• Robust online game­play sup­port, includ­ing NAT tra­ver­sal, Ded­i­cated servers, Friends lists, Voice chat, Global Chat room sup­port (chat to your bud­dies even if they are in dif­fer­ent servers, or play­ing the single-player cam­paign) and more.
• Sophis­ti­cated Ani­ma­tion / Motion blend­ing sys­tem allow­ing dynamic com­posit­ing of animations
• Cut­ting edge physics engine, sup­port­ing com­plex vehi­cles, rag­doll, break­able objects and much more
• DirectX & OpenGL ren­der­ers, with both PC & Mac support
• and Much, Much More!