1. A method comprising: receiving, at a set of one or more server computers, a request from an interface associated with a client device for a web page created in a specific language, the web page comprising content in the specific language, one or more elements in a first markup language used by an interface of the client device to display the content, and one or more elements in a second markup language, the second markup language being an intermediate non-scripting language different from the first language; extracting, with at least one server computer in the set of server computers, a locale-specific preference from a header in the request, the locale-specific preference in the header further including one or more entries that each indicate a preference level for document languages; selecting, with at least one server computer in the set of server computers, a locale-specific module corresponding to the locale-specific preference, the selected locale-specific module built in a language supported by a script associated with the requested web page using one or more user-supplied definitions associating an element of the webpage in the second markup language with one or more locale-specific formattings; sending, from at least one server computer in the set of server computers, the locale-specific module to the client device for storage at the client device; and sending, from at least one server computer in the set of server computers, the requested web page to the client device for storage at the client device, wherein, when the client device encounters the element of the web page in the second markup language when executing the script, the client device uses the locale specific module to determine the one or more locale-specific formattings.