JSON

{
  'Windows':
    {
      '7': 
        [
        {
          browser: 'ie',
          browser_version: 8.0,
        },
        {
          browser: 'firefox',
          browser_version: 2.0,
        },
        {
          browser: 'chrome',
          browser_version: 14.0,
        } ...
        ],
      'XP':
        [
        {
          browser: 'ie',
          browser_version: 7.0,
        },
        {
          browser: 'firefox',
          browser_version: 10.0,
        },
        {
          browser: 'chrome',
          browser_version: 14.0,
        } ...
        ],
    },
  'OS X':
    {
      'Snow Leopard':
        [
        {
          browser: 'firefox',
          browser_version: 11.0,
        },
        {
          browser: 'chrome',
          browser_version: 14.0,
        }, ...
        ],
      'Lion':
        [
        {
          browser: 'firefox',
          browser_version: 11.0,
        },
        {
          browser: 'chrome',
          browser_version: 14.0,
        } ...
        ],
    },
  'ios':
    {
      '4.0':
        [
        {
          browser: "Mobile Safari",
          browser_version: null,
          devices: ["iPhone 4"],
        }
        ],
      '6.0':
        [
        {
          browser: "Mobile Safari",
          browser_version: null,
          devices: ["iPhone 4S (6.0)", "iPhone 5", "iPad 3rd (6.0)"],
        }
        ]
    },
}