7. A system comprising: one or more devices to: receive, from a user, a request for a first web page; obtain the first web page; identify a word or phrase in the first web page based on a number of times that the word or phrase occurs in the first web page and a frequency with which the word or phrase occurs in a language of the first web page; determine one or more terms based on personal information relating to the user; form a search query based on the identified word or phrase and the one or more terms; identify a second web page based on a search performed by a search engine using the search query; insert a reference to the second web page within the first web page to form a modified first web page; and output the modified first web page.
7. A system comprising: one or more devices to: receive, from a user, a request for a first web page; obtain the first web page; identify a word or phrase in the first web page based on a number of times that the word or phrase occurs in the first web page and a frequency with which the word or phrase occurs in a language of the first web page; determine one or more terms based on personal information relating to the user; form a search query based on the identified word or phrase and the one or more terms; identify a second web page based on a search performed by a search engine using the search query; insert a reference to the second web page within the first web page to form a modified first web page; and output the modified first web page. 11. The system of claim 7 , where the personal information includes at least one of a geographical location of the user, information provided by the user when registering an account, or information based on a browsing history of the user.