Syncthing

SyncTrayzor will encapsulate SyncThing within a regular program window. Can be closed and/or minimized to tray and start-up minimized as well. You can still access the web interface if desired. The SyncThing executable keeps a (ugly) taskbar slot constantly open, SyncTrayzor fixes this. Get it here, https://github.com/canton7/SyncTrayzor
Also, I would like to add that it works just fine on Windows 10 x64 (TP-10130) without a hitch.

I sought out an alternative to Bitorrent Sync and SyncThing+SyncTrayzor takes care of my needs.

If you're familiar with Resilio Sync, then you can think of Syncthing as the free and open source version of it. They share much of the same features and functionality.

I think Resilio Sync is a tad faster than Syncthing, but Syncthing's speed is still good. I'm sure it would be even faster if I could figure out how to stop relying on a relay. Speaking of relays, it's some term that the Syncthing manual uses to describe one way of how data is being transferred. That manual is quite in-depth, and is currently beyond my level of comprehension. Yes, Syncthing is quite configurable. You can get a very fine level of control over its configuration, to the point of breaking something if you mess up, whereas in Resilio Sync you would have to pay for some of the advanced features Syncthing already has.

In terms of interface, I think Syncthing's is quite nice to look at and use. With just Syncthing (not SyncTrazor for Windows), you will have to open a browser to get to its GUI. On the left, you have a list of folders that you have chosen to be shared among some of your devices. On the top right, you can view information about your current device, and on the bottom right, you get a list of all the devices that are currently connected.

Upon first setting up, it took some effort to get Syncthing working properly. I admit that I felt a little lost while getting it to work. Even after making it work the first time, it didn't always work the weeks following that. After a few months, however, I can say that Syncthing is running smoothly now.

A little note on when it syncs: this may be just my experience, but I have gotten a lot of files with "sync.conflict" appended to the end of its name. It's not exactly a big deal and can be resolved pretty easily, but it's something to be aware of.

If you are unsure of how you should use Syncthing, I'll tell you about my own use case. I have a few computers and a tablet. One computer has a good sound system. Another is my main work computer for essays and whatnot. My tablet is for note-taking during school. I set up a folder containing all my music files between the two computers. Between my work computer and my tablet, I have two shared folders, one that is extremely organized and holds all my important stuff, and another that is just a sandbox for dumping stuff to organize later. After I finish my classes for the day, I run Syncthing and all my work gets sent to my work computer, then I can view my notes on the big screen. No "cloud" needed!

By the way, you can run Syncthing and Resilio Sync together on the same folder. I was looking for a way to get my iOS powered machine in on the fun, since Syncthing isn't available for iOS.

Awesome tool when working properly. Breaks often, suddenly can't sync for whatever reason. Also no native Windows service support, so need to be logged in for it to run or use alternative method to run as service. Has great promise.

Killer feature for me: synchronization works even with a router with no internet connection at all.

I recently switched over to Syncthing from Bittorrent Sync, and at first I couldn't really figure it out. (Basically if you want similar basic functionality, don't check Master folder on any shared folder).

Anyways after a little experimenting, I found it runs in the background really well. Set and forget. Everything stays updated.

I would really love to see some kind of 3rd party security test be done on it to see whether it's as good as it says it is :)

Why it makes so difficult to implement your own private server, why the code DOES NOT allow private relay server to use only by you and colegues/family ?? You are obligated to use external not know relay servers and A global server and NOT your own domain name/server for use? Why it doesn't let you use your own PGP public/private keys? A little strange to say the least! With this security flaws I prefer to use my own SFTP with public private key and make sync folders!

By the way, just check your firewall log, I bet even TOR has less connections...

[Edited by cvzalez, May 23]

Automatic crash reporting. See https://github.com/syncthing/syncthing/releases/tag/v1.2.0
This costs it 2 stars. The feature appeared today. Upon starting up the app on 2 of my PCs, a message appeared giving me an opportunity to opt out. On a 3rd PC, which runs around the clock, with Syncthing always on, I did not see a message to opt out. To disable automatic crash reporting, according to https://docs.syncthing.net/users/crashrep.html , one must go to "advanced configuration dialog" (not "settings," which only allows one to set anonymous usage reporting). When you click on advanced configuration dialog, a window opens with the following warning: "Be careful! Incorrect configuration may damage your folder contents and render Syncthing inoperable." When I checked, there weren't other instructions. I clicked on "options," and a number of settings appeared. One of these settings, Crash Reporting Enabled, was unchecked. I am going to presume that Crash Reporting Enabled is the same thing as automatic crash reporting. So, for my 3rd PC, apparently, I have not received an opt out notice but crash reporting has not been enabled. Maybe this will change if I restart this PC at some point (I already restarted Syncthing several times)? I don't know, but this will be one more thing that I am going to have to check for a while. Disenchanted long ago with Resilio, I have been using Syncthing. Today's change is disappointing.

The Windows and Linux applications work pretty well most of the time, but have some bugs. I once tried to sync a file with a backslash in the name, for instance, and even though the file has been thoroughly deleted from all systems, Syncthing hasn't forgotten about it and still randomly pops up errors about having an invalid filename. If there are filenames with characters that are invalid on one of the synced systems, Syncthing just refuses to sync them, which is a major flaw that the developers refuse to fix. It should sync them anyway with a mangled name or in a special folder to allow you to rename them from either end.

The syncing is also unreliable. I'll edit a file at work and then come home to find it hasn't synced. But then if I edit and save the home copy, it will suddenly try to sync and now there's a sync conflict.

The Android app is completely useless, since it doesn't support writing to external SD cards. What good is a syncing app that can't sync? Other apps have no problem with writing to any folder on the external SD card, after asking permission, but Syncthing cannot for some reason, so it's useless.

Hopefully someone else will write an Android app that supports the syncthing protocol but can actually delete files at both ends.

This is what I have been always looking for. Ditched my former Onedrive, Dropbox, Drive, MEGA, all for this!

Decentralized and efficient ! It can be used as a backup tool too. Only the Android clients are sometimes a bit off.

It's easy to deploy and use. My favorite feature is that it can be used to sync files between servers. The android client is some low-quality one though, it consumes too much cpu and renders the phone unusable.

I wish it worked. I've been syncing many folders with many thousands of files over several years and it always has problems. I've just gotten used to it saying things like "The following folder has failing transfers" and "Failed items: 32,345". The syncing is very fragile. I hope it hasn't lost me any data.

Good way to wirelessly transfer gigabytes upon gigabytes of audio from my PC to my new smartphone and keep it synchronized with the changes I make and the restructuring I do on my PC. I also made a bidirectionally synchronized sharing directory, and I back up some directories from Android to PC.

Open Source, Cross Platform, Portable but GUI require web browser