20. A method implemented by a computing device configured to utilize a script file, the method comprising: accessing, by the computing device, a web document, the web document having a uniform resource locator (URL) for a script file, wherein the web document also includes a unique identifier for the script file appended to the URL; determining, by the computing device, that the computing device recognizes the unique identifier appended to the URL of the script file; determining, by the computing device and based on the unique identifier, whether the script file is located at a same server as that specified by the URL for the script file, or that the script file is located at a script file repository located at a different server from that specified by the URL for the script file; and in response to the determining that the script file is located at the script file repository located at the different server from that specified by the URL for the script file, obtaining, by the computing device, the script file from the script file repository using the unique identifier.
20. A method implemented by a computing device configured to utilize a script file, the method comprising: accessing, by the computing device, a web document, the web document having a uniform resource locator (URL) for a script file, wherein the web document also includes a unique identifier for the script file appended to the URL; determining, by the computing device, that the computing device recognizes the unique identifier appended to the URL of the script file; determining, by the computing device and based on the unique identifier, whether the script file is located at a same server as that specified by the URL for the script file, or that the script file is located at a script file repository located at a different server from that specified by the URL for the script file; and in response to the determining that the script file is located at the script file repository located at the different server from that specified by the URL for the script file, obtaining, by the computing device, the script file from the script file repository using the unique identifier. 22. A method according to claim 20 , wherein when the unique identifier is unrecognizable to the computing device, obtaining the script file using the address included in the URL includes obtaining, by the computing device, the script file using an address indicated in a src attribute of a <script> tag in the web document.