Rendering excel reports

[SM]

We have an application development proposal in which we will develop excel
reports ( one with about 11 worksheets ) and let the user open/save the file.
User will click a button on web page and save or open the report.

My question is whether we should do it by using native excel object on
server or rendering the output in excel on the client.

Ours is a multi user environment.

 

[Thomas]

If you render a spreadsheet on the client side, there shall be a
toolbar item that enable the user to save the spreadsheet as Excel.

 

[SM]

We have multiple worksheets in the renedered excel file.