Valve, the creators of Counter-Strike, Half-Life, and Portal, have released Left 4 Dead for Mac, a co-op action horror game that casts up to four players in an epic struggle for survival against swarming zombies and mutants.

Although the gaming studio was able to deliver Left 4 Dead 2 (the sequel) to Mac gamers on precisely the same day as PC gamers, the original was stuck in development because of several compatibility issues with Mac hardware and the Mac operating system.

That’s not the case anymore, as Valve gladly announced Left 4 Dead availability for the Mac via Steam, the company’s a digital distribution, digital rights management, multiplayer and communications platform.

“Updates to Left 4 Dead have been released,” reads an announcement on steampowered.com. “The updates will be applied automatically when your Steam client is restarted. The major changes include:

Left 4 Dead
- Added Mac support for Left 4 Dead
- In Versus mode Tanks will spawn in stasis until a human player takes over. Tanks in stasis are invisible and invulnerable, and won't move or attack
- Tank speed is no longer reduced when on fire
- Allow players on the Infected team to manually spawn during finales
- Added a vote option toggle All-Talk
- Any Special Infected that causes a Survivor to stumble into a "ledge hang" situation will receive 50 points
- Bullets that first pass through an infected character before striking a Survivor are now ignored as friendly fire
- In Versus mode car alarms will now trigger anytime a Special Infected pulls or stumbles a Survivor into an alarm car
- Protected console commands that can be used to lag or crash servers”

Visit Valve’s steampowered.com web site to get the discounted Left 4 Dead for just $9.99, or to get Left 4 Dead and Left 4 Dead 2 for just $14.99 for a limited time.

Those who own the game on their Windows PCs, can download and play for free on their Macs as well.