If this is for viewing only, you have one free option available for server. You can run the schematics gp tool to convert diagrams to features and just convert all your diagrams into features. This results in a feature dataset for the diagram template and then a feature class for each schematic feature class. Then all the diagrams are just individual records in the dataset/feature classes. You can then just put those into a map and publish with nothing more to do with Schematics. The trick is that on the web client side, you will need to provide a way for the user to pick which diagram they want to view and then you just dynamically apply a definition query to the layers DiagramObjectID=?. At 10.1, the diagram layer itself is recognized by the server publishing mechanism, so you don't have to convert to features first.
