Google returns as a sponsor and the rules are changed to require full disclosure of exploits and techniques used. Web browsers Google Chrome, Internet Explorer and Firefox along with Windows 8 and Java have been exploited.
At Pwn2Own 2013, French security firm VUPEN has successfully exploited a fully updated Internet Explorer 10 on Microsoft Surface Pro running a 64-bit version of Windows 8 and fully bypassed Protected Mode sandbox without even crashing or freezing the browser.  VUPEN team has next exploited Mozilla Firefox, Adobe Flash, and Oracle Java to win a total prize of $250,000, the highest payout to date.
Nils and Jon from MWRLabs were successful in exploiting Google Chrome using WebKit and Windows kernel flaws to bypass Chrome sandbox and win $100,000.
George Hotz exploited Adobe Acrobat Reader and escaped the sandbox to win $70,000. James Forshaw, Joshua Drake, and Ben Murphy independantly exploited Oracle Java to win $20,000 each.
Apple Safari on Mountain Lion was not targeted as no teams showed up.