AppFresh is an utility that helps to keep all applications on your Mac up to date by checking the internet for new releases and making downloading and installing a breeze
JUF (Java Update Framework) is a framework that makes easy the implementation of automatic updates of software. It's written in Java and it has been tested in windows and linux but it's hoped it will run in any os with a Java Virtual Machinne.
This application can check for available updates. As soon as your application starts it can look if an update is available and notifys the user. As it is written in Java it is platfom independent.
Short answer: Jauus is a software patching programs that works over the internet by making a single TCP connection to the host server. It works on any java supported platform for -ANY- language or type file; ASCII, binary, java, VB, C/C++ Perl it doesn't matter. The client/server see each file as objects and pass them over the network as such.