Files, or other data, may be stored in a package, and the contents of the package may be retrieved incrementally and/or on-demand. In one example, files are packaged into a ZIP file or similar type of package. Additionally, metadata is added to the package that describes the contents of the package at the sub-file level, thereby allowing portions of files to be retrieved by appropriately-configured software. When the package is to be used on a local machine, placeholder files may be created on that machine, which are to be populated by the package's contents at a later time. When a request for data in the package is made, if the data does not reside locally, then a request for the specific data (possibly at the sub-file level) is made, and the placeholder files are populated with the actual package data.