Being able to view files directly in my browser is nice. Forcing a download just so that I can open the same file in the same program is just annoying. But be

Being able to view files directly in my browser is nice. Forcing a download just so that I can open the same file in the same program is just annoying. But be careful! If you serve user-uploaded, untrusted files from the same domain as everything else, that's a great way to make yourself vulnerable to XSS.