A script package is simply a disk directory containing script files, one file per service. The name of the directory is the name of the package, and each file is named for the service it contains. So "MyPackage.MyService" would be MyPackage/MyService.lua (assuming the Lua script engine is in use).

Once support for folded file systems is added to the engine, it will be possible to pack up the directory into a .zip file or similar for easy distribution.