It is official. It was confirmed this Monday that Valve will bring its on-line distribution service, Steam, and titles from its large library of games to the Mac this April, including valve titles like Left 4 Dead and the upcoming Portal 2, as well as games from other publishers to Apple computers for the very first time.

At the moment Steam has over 1,000 games and 25 million user accounts and is said to serve around 70% or the digital download market.

“The traditional model has always been that you have these really extended development times … where you do nothing for customers for several years and then you try to drive everybody into the theaters or into the stores on a given date,”

“It makes it hard to steer your decisions based on customer feedback, and customers don’t particularly like that. They would like to have the experience of being part of an entertainment community where they’re getting something on a daily or more frequent basis.”

“The Mac represents a great opportunity to deliver these things.”

Also with Steam Play if players already own the PC versions of Valve games, they will get Mac versions at no extra charge. In addition Steam Cloud allows players to save in-progress games online, then call up those saved games no matter which version they’re playing.

“We are treating the Mac as a tier-1 platform so all of our future games will release simultaneously on Windows, Mac and the Xbox 360,”

“Updates for the Mac will be available simultaneously with the Windows updates. Furthermore, Mac and Windows players will be part of the same multiplayer universe, sharing servers, lobbies and so forth. We fully support a heterogeneous mix of servers and clients. The first Mac Steam client will be the new generation currently in beta testing on Windows.”

Valve’s first simultaneous release for Mac and Windows will be Portal 2. However Telltale Games announced last month that it would be moving to Mac.