Implementing Open XML SDK 2.5 to server

Question

Considering that I already installed XML SDK 2.5 to the server, will it require me to also install MS Office in the server for the program to run or for the client to use the program.

Answer 1

Short answer:
NO need to install MS Office on the server,
"NO" need to install MS office on clients

Let me try to explain this briefly.

OpenXml is a file format: compressed package containing xml files.

OpenXmlSDK is a wrapper for this file format: class that allow you to create package, or modify it's xml content, it doesn't require MS office, and it's the real advantage in server side application.

So no need to install MS Office on the server.

Then you could imagine that clients are able to create OpenXml files on the fly and download them on their computers. If they have not MS Office installed, they won't be able to open the created files, but the files are still valid.

So "technicaly", clients do not need to have MS office installed to interact with your server application.