Today Valve President Gabe Newell too part in an Ask Me Anything session on Reddit responding to quite a few questions from the fans. Newell gave some information on the projects in the works at the company, and on a rather broad range of issues.

First of all, he mentioned that the company is aiming to develop all its future games using the Source 2 engine, mentioning that there are "some unannounced projects" in the works.

"We are continuing to use Source 2 as our primary game development environment. Aside from moving Dota 2 to the engine recently, we are are using it as the foundation of some unannounced products. We would like to have everyone working on games here at Valve to eventually be using the same engine. We also intend to continue to make the Source 2 engine work available to the broad developer community as we go, and to make it available free of charge."

Asked about what is the direction he feels Valve should take for the future, Newell mentioned the intention of broadening the range of experiences the company can create, which comes through the investment in hardware. He also hinted that at least some of the projects in the works are virtual reality games.

"The big thing right now is broadening the range of options we have in creating experiences. We think investing in hardware will give us those options. The knuckles controller is being designed at the same time as we're designing our own VR games.

Much more narrowly, some of us are thinking about some of the AI work that is being hyped right now. Simplistically we have lots of data and compute capability that looks like the kinds of areas where machine learning should work well.

Personally I'm looking at research in brain-computer interfaces."

He also explained how developers are assigned to various projects:

"It changes all the time. There's no fixed ratio, and people move to the project where they think they can create the most value."

Asked whether Valve is planning to continue the Left 4 Dead series, Newell gave a vague, but tentatively positive response.

"Products are usually the result of an intersection of technology that we think has traction, a group of people who want to work on that, and one of the game properties that feels like a natural playground for that set of technology and design challenges.

When we decided we needed to work on markets, free to play, and user generated content, Team Fortress seemed like the right place to do that. That work ended up informing everything we did in the multiplayer space.

Left 4 Dead is a good place for creating shared narratives."

Asked which Valve Game was his favorite, Newell mentioned Portal 2 for single player, and DOTA 2 for multiplayer. He also explained why he did not bring up Half-Life.

"The issue with Half-Life for me is that I was involved in a much higher percentage of the decisions about the games, so it's hard for me to look at them as anything other than a series of things I regret. There's no information in my response about what we'll do in the future. It's simply easier for me to be a fan of things that in which I was less directive."

He followed up later in the AMA, explaining the issue in more detail.

"If you are involved in a game, everything ends up being a set of trade-offs. Anything in a game is a sacrifice of things not in the game. I just feel those more personally about Half-Life for a bunch of reasons.

And Xen."

He also confirmed that the movie(s) based on the Half-Life/Portal universe produced by  J.J Abrams are still coming.

"Yep. They're coming."

Asked about the state of Half-Life 3 and Half-Life 2 Episode 3, Newell responded:

"The number 3 must not be said."

That said, he confirmed that the company is still working on full-fledged single player games, and also commented (sarcastically) on the legitimacy of the anonymous source that mentioned the cancellation of Half-Life 3 in a recent interview.

"I personally believe all unidentified anonymous sources on the Internet"

On the bright side, Newell also confirmed that a new IP taking place in the Half-Life/Portal universe is a possibility.

He then talked about the reason why Valve at times appears not to talk to its customers as much as other developers.

"That’s right. Another way to think about this, and the way we talk about this internally, is that we prefer to communicate through our products. We are all pretty devoted to reading and listening to the community - everyone here believes it is an integral part of their job to do so. And when it comes time to respond, we generally use Steam - shipping updates that address issues or add functionality. Obviously this doesn't work for everything. Working this way imposes latency on our communication - it takes longer to ship and update than to do a blog post. This can lead to the feeling of an echo chamber, where it seems like Valve isn't listening. We’re always listening. So sometimes the latency is rough for everyone, including us when we want to address issues quickly. On balance we think it's usually worth the trade-off."

Will Half-Life 3 ever happen? Gaben did not say, so all we can do is keep hoping.