A interesting issue is having a cache that works in both directions. For example CVS and subversion work in this way. They store a cache of what is on the server and then the user can change that and then "sync" it back with the server again.

Webstart doesn't allow the user to change the cache and then sync it back up again. Also webstart has a higherlevel view. It isn't just a file system. You start at a jnlp file which then references other files and then all these files jnlp and resource files are cached locally.

Both webstart and subversion have incremental downloads.

workspace.jar has this basic functionality too but in integrates the dependency checking at the same time. This is similar to what webstart does. The jnlp file defines the depedencies.

We can try to build off of one of these existing systems or we can do it ourselves. One issue is the ability to incorporate the permissions and security into the system. The dependencies should be easy to add. But adding all the signing needed to make it secure on unsecure storage might limit our choice.

I believe that webstart has this built in. I know we can change workspace.jar to do this, but it will be a bit of work.

So the main issues I see with our availalbe technologies are:

• upload and download ability
• flexible enough to support security additions so it is safe to use it in an unsecure environment.