Like many companies, we're running a Windows-based file server which all users have access to the root, then each folder is access controlled appropriately. It's behind a VPN and works reasonably okay except now as users expand to using Macs, smart phones, tablets, home computers, etc, the traditional fileserver/VPN solution is starting to seem a bit antiquated.
I started looking into S3 with ExpanDrive as a front-end to Windows and Mac, and probably a read-only (or simple read/write) application as part of our internal web application. The idea being users could typically use ExpanDrive to invisibly access the S3 bucket while on their computers, opening and saving files as they do now, and still have limited use with other devices.
But after digging into it a bit, it seems non-trivial (impossible?) to set up user-level permissions on S3. While the idea of a WebDAV enabled S3 front-end did pass my mind, it seems too kludged together.
Are there any enterprise-level services out there that do what users are used to a Windows-type environment?