id Software's mobile development branch has been shut down so the studio may concentrate on Doom 4, John Carmack confirmed during his QuakeCon 2012 keynote speech.

"We did make the decision to close up our mobile development, which saddens me a lot, in that I love doing the mobile work…but we had some developers on there that we wanted to bring onto the Doom 4 project,” said the id co-founder.

"It was looked at as something that; yes, this is fun, this is fun for the company and its entertaining and it makes money, but it's not a grand slam sort of thing on there. The Bethesda family really is about swinging for the fences. I hope we get back to mobile in various ways in the future, but the big real aim is blockbuster, AAA titles.”

Carmack confirmed that id had finished an unannounced iOS project, but further details were not forthcoming.

"We're going to hold off until some appropriate time," he said.

Carmack also mentioned that Doom 4 would feature support for the Oculus Rift.

"I'm excited for once Doom 3 ships and gets out there, I'll put all this stuff into the Doom 4 platform, which will be nice to take our current top-of-the-line stuff and have that in virtual reality," he said.

As for a Doom 4 release date, the game “will be done when it’s done”, said Carmack.

"Every decade there will be a Doom, but hopefully we can do better than that."