When people need to synchronize, backup or frequently share files/data between a variety of devices (including computers and mobile phones), any traditional ways of file transfer are relatively inadequate. For example, a lot of cloud storage services like Dropbox have more and more and increasingly obvious limitations or restrictions. These include: files have to be uploaded to their servers for transfer, very limited disk space capacity, pretty high requirements on Internet connection speed and stability, limitation of transmission speed and bandwidth usage, very few acceptable file types, not high enough security, easy to be blocked by some countries, expensive cost, and so on. Thereupon, Resilio Sync (formerly called BTsync, full name BitTorrent Sync, now Sync for short) came out.

FTPbox this free and open-source lightweight app is specially designed for webmasters or advanced users. It enables your free or paid FTP file space to instantly turn into a private cloud storage server that can perform two-way synchronization with your local folders on computer, just works like Dropbox's web disk.