Egnyte's secret sauce is web-based Distributed Authoring and Versioning or WebDAV, an HTTP extension developed by the IETF that allows computer users to edit and manage files collaboratively on remote web-based machines.
Egnyte is an online warehouse that uses WebDAV (as well as FTP/FTPS) for access. There are no Egnyte VMs as gateways, only accessibility to Egnyte through WebDAV access as a share — much like how CIFS works. Access can be set per folder for users and groups with read only, read/write, and read/write/delete permissions.
We could also use Egnyte's Web page to upload or download files via a Java applet. WebDAV support is hardly mentioned in the documentation, but there is a supplied Egnyte application which mounts the WebDAV share "behind the scenes," which is what most organisations would use. Therefore, most people wouldn't even know that it's using WebDAV.
The Egnyte application runs on Windows, Mac or Linux, and we tested it on Mac. The WebDAV file system is mounted as a peer drive on a host, either a server on your network, or a user/workgroup share. The products that perform this gateway service vary from operating system to operating system and most are native.
Windows 7, however, seems to require third-party software (of which there are many varieties for many operating systems) or running Windows IIS7 on client or server desiring peer access to WebDAV resources.
The rationale behind WebDAV is sharing files, and versioning metadata is included with file storage, along with file share/locking mechanisms. File sizes are limited to 15GB via ftp/ftps, 500MB via Java applet, 10MB via single file uploader, but it's possible to send truly huge files (15GB+) via a physical drive transfer.
Egnyte doesn't have bandwidth charges, rather there's a tier of use broken into standard and power user licence packs with gradients regarding user count and storage size.