Valve has announced that Steam for Mac is now available to download at www.steamgames.com. Gamers who download Steam between now and May 24^th will receive a free copy of Portal (this offer is also available for Windows users).

“The Mac is a great platform for developers,” said Gabe Newell, president of Valve. “And it’s also great that we now have the ability to connect with Mac gamers via Steam. This is the beginning of a groundswell of games coming out for and fully utilizing the openness and power of the Mac.”

Every Wednesday, a new group of games highlighting an area of Steam functionality will be released. This week’s titles show off Steam Play and include:

And Yet It Moves

Atlantis Sky Patrol

Bejewelled 2 Deluxe

Bob Came in Pieces

Bookworm Deluxe

Braid

Brainpipe

Chocolatier: Decadence by Design

Chuzzle Deluxe

City of Heroes: Architect Edition

Civilization IV: The Complete Edition

Cooking Dash

Diaper Dash

The Dig

Diner Dash: Hometown Hero

DinerTown Detective Agency

DinerTown Tycoon

Dream Chronicles: The Chosen Child

Escape Rosecliff Island

Fairway Solitaire

Fitness Dash

Football Manager 10

Galcon Fusion

Gemini Lost

Guns of Icarus

Hotel Dash Suite Success

Indiana Jones and the Fate of Atlantis

Indiana Jones and the Last Crusade

KrissX

Loom

Luxor

Luxor 3

Luxor: Mahjong

Machinarium

Mahjong Roadshow

Max and the Magic Marker

My Tribe

The Nightshift Code

Nightshift Legacy: The Jaguar’s Eye

Parking Dash

Peggle Deluxe

Peggle Nights

Portal

Professor Fizzwizzle and the Molten Mystery

Quantz

Sam & Max: The Devil’s Playhouse

Tales of Monkey Island Season 1

Toki Tori

Torchlight

Trijinx: A Kristine Kross Mystery

Unwell Mel

Valarie Porter and the Scarlett Scandal

Wandering Willows

Wedding Dash 2: Rings Around the World

World of Goo

Zenerchi

Zuma Deluxe