A variety of databases exist that define browser device features and capabilities.
Zend_Http_UserAgent provides the ability to utilize the database
of your choice via a features adapter interface.
The features adapter is passed a request array that contains the User-Agent string and any other relevant HTTP headers and environment pertinent to detecting the device in use. Additionally, if any adapter-specific configuration might be needed, an additional configuration array will be provided. The adapter must then return an array of device capabilities.