I am writing an application that will require a fair number of large external files, but every user might not want all of them. Just as I was thinking how the best way to distribute the app without making a complex installer (large download anyway) or stripping down the app too much, I received a "Software Update" notification. Then, the little light bulb went off I can make the installer build all of the essential support files, and then allow the user the option to do a "Software Update" and pull down the files at their leisure. Does anyone know of a link that shows some sample source code that demonstrates how Apple does their own "Software Update"? I would need "two flavors" of it: 1. User Initiates -- If they want more of the support files, then can use a menu option to make a request. 2. Server Side Initiates -- If a "necessary support file changes", it would be great if I could notify everyone that is connected, the way Apple does. I know there is probably a mountain of code to handle this request, but if I could just find out the core API files I would be able to handle all of the tedium required to make this work. Thanks in advance to all who share their ideas!