I want to display XML as excel spreadsheet on the browser using XSL. Any suggestions.

You should have mentioned whether you have to use client
side trasformation or whether you can leverage a more
sophisticated server environment, and how well the client
environment is controlled.

You can transform the XML to CSV (comma separeted values)
or perhaps HTML for more recent Excel releases.
If the transformation is on the client, you'll probably
have to start Excel from a script.

If you want to do the transformation on the server and
have no control of the client configuration, the safest
way is to generate XLS files, using tools like Apache POI
 http://jakarta.apache.org/poi/index.html