1. An apparatus comprising: at least one processor; memory coupled to said at least one processor storing: a markup language document containing: a first instance of a markup language element having an attribute with a first, platform-independent value; a second instance of said markup language element having said attribute with a second, platform-specific value, wherein said platform is a platform to which an instance of said markup language element is to be deployed; and an indicator that said second value overrides said first value; and machine-executable code which, when executed by the at least one processor, generates from said markup language document a serialized markup language document, said generating comprising replacing both of said first instance and said second instance with a single instance of said markup language element having said attribute with said second value, said serialized markup language document containing said single instance but not containing either of said first or second instances; and a network interface for use in uploading the serialized markup language document for deployment to said platform.