No it is not being developed by infinity ward but by Treyarch & produced by Activision.
There are no zombies on Call of Duty Modern Warfare 3. To get the Zombies you need to play the Treyarch developed Call of Duty Game Black Ops and not the Infinity Ward developed MW3
No Call of Duty Modern Warfare 2 was developed by Infinity Ward and it was the Treyarch developed games like Call of Duty Black Ops and World at War Map Packs which had the Zombies
I'm assuming your asking for CoD4, WaW, MW2, and Black Ops. CoD4 and Mw2 were developed by Infinity Ward. WaW and Black Ops were developed by Treyarch. They are both under the publishing company Activition.
Infinity Ward
Infinity Ward developed some of the games and Treyarch developed others both for Activision
The game was developed by Treyarch and published by Activision and designed by Margaret Tang
The Infinity Ward Jason West (Infinity Ward president, game director, co-CCO, and CTO) and Vince Zampella (CEO and co-founder of Infinity Ward) were dismissed and replaced on an interim basis by Activision CTO Steve Pearce and head of production Steve Ackrich. Activision CEO Bobby Kotick addressed Infinity Ward studio heads on March 2, 2010 about Zampella and West's dismissal and the outcome of those and future meetings is unknown.
The Call of Duty games are published and owned by Activision. While the studio Infinity Ward primarily still develops them, Treyarch has also developed several of the titles with the release of the studios' games interlaced with each other.
It was developed by Infinity Ward and released by Activision
No MW4 will not come out at all. Call of Duty Ghost will come out and it was developed by Infinity Ward who developed the Modern Warfare series of Call of Duty
The company that made Call of Duty Black Ops is Treyarch.
Call of Duty is one game