I'm not sure I'm asking the right question here, but I'm looking to provide web based functionality from one ASP.NET application to another remote 'portal-like' application. Is it possible to simply give the portal a DLL? As an example, let's say the SaaS web app has a patient-entry form that I want to be able to use from the portal application. I would like the portal app to be able to set preferences (permissions, color, style, etc), make a function call, and have that capability presented within a certain div or something. Is there any .NET technologies that provide this kind of integration?
EDIT:
Here is a link to a quick diagram I made trying to describe the scenario: http://img.ly/ESG. I know there are other ways of doing this (eg JSON-P calls), but I need to give the portal developers something they can control on their end. Also, if anything changes they'll know I will send them a new version of the DLL which will indicate to them the new functionality.