8. A server having one or more processors configured to perform operations comprising: outputting, to a developer of a web page in a source language, an offer to opt-in to a translation feature that enables one or more other users to translate the web page to a different target language; receiving, from the developer, a first request to opt-in to the translation feature; and in response to receiving the first request to opt-in to the translation feature: generating and storing a copy of the web page; obtaining, from the one or more other users, translations of at least a portion of the web page from the source language to the target language; modifying the web page copy based on the obtained translations to obtain a translated web page, the translated web page being a translated version of the web page; detecting a second request for the web page from a computing device associated with the target language; and in response to detecting the second request, outputting, to the computing device, the translated web page with additional content relevant to the computing device or a user associated with the computing device.
8. A server having one or more processors configured to perform operations comprising: outputting, to a developer of a web page in a source language, an offer to opt-in to a translation feature that enables one or more other users to translate the web page to a different target language; receiving, from the developer, a first request to opt-in to the translation feature; and in response to receiving the first request to opt-in to the translation feature: generating and storing a copy of the web page; obtaining, from the one or more other users, translations of at least a portion of the web page from the source language to the target language; modifying the web page copy based on the obtained translations to obtain a translated web page, the translated web page being a translated version of the web page; detecting a second request for the web page from a computing device associated with the target language; and in response to detecting the second request, outputting, to the computing device, the translated web page with additional content relevant to the computing device or a user associated with the computing device. 9. The server of claim 8 , wherein the operations further comprise identifying the web page as being at least one of a high-traffic web page having greater than a particular rate of user visits and a highly-requested web page for machine translation having greater than a particular rate of user machine translation requests, wherein outputting the offer is performed in response to identifying the web page as being at least one of the high-traffic web page and the highly-requested web page for machine translation.