1. A method comprising: responsive to receiving a character string from an instant messaging client, determining if the received character string comprises a request for a network resource; responsive to determining that the received character string comprises a request for a network resource: comparing the received character string with a list of previously visited network resource addresses, from browser history; and identifying a substantially identical network resource address from a list of previously visited network resource addresses that comprise the string; and communicating the substantially identical network resource address to the instant messaging client application; and storing, by web browser software, records of network resource addresses in said browser history and identifying descriptions of all resources visited using a set of application programming interfaces (APIs) which allow the web browser software to be addressed by other software.