DeviceDetector 是一个用 Ruby 编写的用来解析各种设备 User-Agent 信息的库，基于及时更新和庞大的 user-agent 库。使用 DeviceDetector 可探测设备浏览器、操作系统、设备类型（桌面、平板、移动、电视、汽车、控制台等）、品牌和型号。

示例代码：

user_agent = 'Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.17 Safari/537.36'  client = DeviceDetector.new(user_agent)     client.name # => 'Chrome'  client.full_version # => '30.0.1599.69'     client.os_name # => 'Windows'  client.os_full_version # => '8'     # For many devices, you can also query the device name (usually the model name)  client.device_name # => 'iPhone 5'  # Device types can be one of the following: smartphone, tablet, console,   # portable media player, tv, car browser, camera  client.device_type # => 'smartphone'

为了提升性能，DeviceDetector 可以把 UserAgent 信息放到缓存中：

DeviceDetector.configure do |config|    config.max_cache_keys = 5_000     # increment this if you have enough RAM, proceed with care  end

项目主页：http://www.open-open.com/lib/view/home/1426930006867