Steam Launches Biggest Free Weekend Ever

Steam has launched what Valve is calling the service's "largest Free Weekend ever", offering free access to ten popular titles all weekend.
The 10 titles available to play for free are:

• Awesomenauts
• Blade Symphony
• Company of Heroes 2
• Don't Starve
• Grid 2
• Injustice
• Killing Floor
• Payday 2
• Trine 2
• XCOM: Enemy Unknown

All these titles are also available to buy at reduced prices.
Source: Valve