On Windows 7 SP1 it uses IE11. Same on Windows 10. On some Windows 8 it might use IE10, which is still not that bad. Sorry, can't tell much about xls/doc. It's

On Windows 7 SP1 it uses IE11. Same on Windows 10. On some Windows 8 it might use IE10, which is still not that bad. Sorry, can't tell much about xls/doc. It's aimed to be a web UI for your app. Normally, you app would be a web server then. So if you want to handle certain requests and open external apps - you surely can do it.