1. When you use Windows Authentication on an app, they are automatically authenticated with the network.

Now you have two options. On the page that links to all the in-house apps,

a) You can simply create a link to each of those apps
b) You can have Windows Authentication enabled on YOUR page, and, when sending the user to the other apps, you pass their windows authentication information so that they needn't login again there. This way, the credentials are passed to those apps, yes, and THOSE apps check security levels, etc., etc.

What do you think now?