Reporting can be done in a number of ways from HTML pages that can be printed to CSS for formatting the printing to reporting tools like Active Reports or SSRS.

For Excel, it depends on what you need. It is not recommended to run Excel on the server. You can using something like Spread.Net or SpreadJS.

>Good question.
>I'm working on a browser-based app now and the printing is the most difficult part of the app.
>You can ask the same question about other peripherals.. scanners, etc., or interfacing with apps like Exel, etc and the answers will be fuzzy.