BitTorrent Sync is a peer-to-peer file sync and share tool that leverages the BitTorrent protocol. Because of its decentralized architecture, it’s an effective means of rapidly distributing very large files.

The company has announced the release of version 1.4, which is still a beta version, but which is featuring some large improvements over 1.3. And the company also states that since the alpha launch last year the company has had 10 million user installs and transferred over 80 petabytes of data.

The major improvements are centered on usability and simplicity. One feature new for 1.4 is the use of links to share without the recipient even having to have an existing account. Once they receive the link — by email, QR code, or other communication channel — the recipient only has to click the link and BitTorrent handles the next steps.

The advanced options include controls on how long a link is usable, how many times it can be used, and management of peering access (shown at the bottom). This last control allows the user to require that all files syncing come from the originating device, and not from other peers with whom they have been shared with.

The earlier Keys approach of giving access to folders is still available (formerly called Secrets), but this is remarkably simple.

The UI for v1.4 is much cleaner and easier to use, including a customizable folder list to show the metadata of interest to you.

v1.4 is available now for Windows, Mac OS X, and Linux, and mobile clients will be updated quickly.

As I wrote in the recent Roadmap on File Sync and Share,

BitTorrent Sync is in another special niche. The product relies on the BitTorrent protocol — an encrypted peer-to-peer service where, after authentication, files are synced and shared directly from one device to another — without passing through the BitTorrent server. This makes transfer of large files much faster, and since no copies are made on a cloud server the possibility of those documents being subject to a government inquiry or some other sort of disclosure is low, or even zero.

And this special niche is one that 80 petabytes have passed through already.