Unison File Synchronizer

From the changelog:<p>&gt; Further improvements to the OS X GUI (thanks to Alan Schmitt and Craig Federighi).<p>Here are Craig&#x27;s commits:<p>- <a href="https:&#x2F;&#x2F;github.com&#x2F;bcpierce00&#x2F;unison&#x2F;commit&#x2F;48f8e1b27edbe2df0a6da272b6694f0d522c710b" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;bcpierce00&#x2F;unison&#x2F;commit&#x2F;48f8e1b27edbe2df...</a><p>- <a href="https:&#x2F;&#x2F;github.com&#x2F;bcpierce00&#x2F;unison&#x2F;commit&#x2F;6645d1793ce843f6fe163c7ad68dc1932ad89500" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;bcpierce00&#x2F;unison&#x2F;commit&#x2F;6645d1793ce843f6...</a><p>Around the same time, Dave Abrahams, now of Apple&#x27;s Swift team, makes an appearance on the unison-hackers mailing list.

I&#x27;ve been working on a spiritual successor to Unison for a few years called Mutagen [1]. It aims to provide more flexible synchronization and tighter integration with filesystem watching, enabling ~real-time remote editing with your local editor of choice. It also adds SSH-style network forwarding, so you can forward network traffic to&#x2F;from remote systems to access remote applications without exposing ports. It currently supports SSH and Docker containers, but additional transports are coming.<p>I&#x27;d be really happy to receive feedback if you have a chance to try it out!<p>[1] <a href="https:&#x2F;&#x2F;github.com&#x2F;mutagen-io&#x2F;mutagen" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;mutagen-io&#x2F;mutagen</a>

Is this project still going? I used to use it a lot for duplicating my project directories between my lap PC and my home PC. It was so powerful and so useful at the time. Honestly I thought it had died.<p>I use Syncthing now. It&#x27;s really useful.

I can&#x27;t praise Unison enough. I&#x27;ve been using it every day for over 10 years and is easily one of the most useful pieces of software I&#x27;ve ever come across. I&#x27;ve donated multiple times over the years.

A few years ago, I was working in a company that used a shared drive on a local Windows network. Several analysts and people from other departments would use the drive to store shared price lists, tables, and other documentation. Part of my job was to keep these data files updated with info on a daily basis.<p>The problem with trying to edit these files was that everyone logged in on the network had access to them and could change them arbitrarily. Or they could even just inadvertently lock the files if they left them open on their PCs. There was no control or change management.<p>I decided to keep the &#x27;canonical&#x27; versions of the files on my PC at work and use Unison to sync them over to the shared network versions of the files once a day. Unison would instantly tell me if anyone other than me had changed the files, and I could investigate further. It was a huge relief knowing that I had proper control over those files.

Unison&#x27;s cool, but I hit some major roadblocks with it, namely: it can&#x27;t run on an heterogeneous network [0,1]. As many others have already suggested, syncthing[2] is the new best tool out there for multi-directional sync.<p>[0] <a href="https:&#x2F;&#x2F;wiki.archlinux.org&#x2F;index.php&#x2F;Unison#Version_incompatibility" rel="nofollow">https:&#x2F;&#x2F;wiki.archlinux.org&#x2F;index.php&#x2F;Unison#Version_incompat...</a> , <a href="https:&#x2F;&#x2F;groups.yahoo.com&#x2F;neo&#x2F;groups&#x2F;unison-users&#x2F;conversations&#x2F;topics&#x2F;11439" rel="nofollow">https:&#x2F;&#x2F;groups.yahoo.com&#x2F;neo&#x2F;groups&#x2F;unison-users&#x2F;conversatio...</a><p>[1] <a href="https:&#x2F;&#x2F;try.popho.be&#x2F;byeunison.html" rel="nofollow">https:&#x2F;&#x2F;try.popho.be&#x2F;byeunison.html</a><p>[2] <a href="https:&#x2F;&#x2F;syncthing.net" rel="nofollow">https:&#x2F;&#x2F;syncthing.net</a>

Unison has been an indispensable tool for me for many years. I keep my desktop and laptop in sync by using an always-on Linode as a sync server.<p>Something I love about Unison is the fact that I can sync files from anywhere on my filesystem without having to move them or replace them with symlinks.<p>I can also sync subsets of my files by defining multiple profiles. I have Unison set up to default to a &quot;common&quot; profile that includes nearly everything, but I can explicitly request a sub-profile if I want. I also have a separate profile that syncs the profiles themselves, so I can make profile changes on one machine and run `unison profiles` to upload them.

Unison efficiently and reliably syncs my website (static blog mostly) between OS X and FreeBSD. It&#x27;s one of those extremely underrated pieces of software that just quietly does an excellent job, yet most people never heard of it and continue to struggle with rsync or similar (syncthing fulfills a somewhat different role). Perhaps because it&#x27;s written in an oddball language, or because the website isn&#x27;t flashy enough.<p>I often evaluate a wide range of software before choosing what I consider best for a job, and many years ago, Unison came out way ahead in such an evaluation. It never failed me.

The Development Status section of the manual mentions a follow-on project called Boomerang¹. It looks like the GitHub repo² only had activity for about 2 years, then stopped. Is that a dead project?<p>¹<a href="https:&#x2F;&#x2F;www.seas.upenn.edu&#x2F;~harmony&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.seas.upenn.edu&#x2F;~harmony&#x2F;</a><p>²<a href="https:&#x2F;&#x2F;github.com&#x2F;boomerang-lang&#x2F;boomerang" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;boomerang-lang&#x2F;boomerang</a>

I use Unison every day to synchronize my work computer and my home computer, using an USB thumb drive as the intermediary. The thing I like the most about this arrangement is that I don&#x27;t need a direct SSH between home and work, that there is no cloud service involved, and that the GUI lets me double check what files are going to be written to&#x2F;from the usb drive before it synchronizes.<p>There is one issue that I have run into though. If I format the USB as fat32 it can&#x27;t properly store permissions. And if I format it as ext4 then I need to make sure that my numeric user ID is exactly the same in both my home and work computers (otherwise the permissions get messed up).<p>Is there a way to make my arrangement more robust so that I can sync files through and USB drive, without needing to use the same numeric user id in all my computers?

I used to use unison to periodically sync files between a host filesystem and a VM filesystem as it was a lot faster - in terms of filesystem performance when not syncing - than using the shared folder functionality provided by the VM.

I&#x27;ve been using Unison since... forever.<p>A hint regarding running the latest Mac binary on Mojave: if the GUI crashes on you, it&#x27;s likely to be an issue regarding syncing file _permissions_ and not just files.<p>This has been biting me for a couple of months now whenever I sync my development tree between Dropbox and OneDrive, since Windows&#x27; WSL tends to set wonky 0x777 permissions on entire file trees, and it is usually those that cause Unison to crash.<p>Otherwise, I&#x27;ve been using it to sync 400K+ files without incident.

Unison is great for keeping multiple machines in sync. I eventually switched to Dropbox for reasons I don&#x27;t recall, but it might be a good time to reconsider. Also, I&#x27;d forgotten, but apparently I even made a (poor) attempt at writing a Unison UI of OS X, some 11 years ago... <a href="https:&#x2F;&#x2F;github.com&#x2F;logandk&#x2F;autoson" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;logandk&#x2F;autoson</a>

I used and loved Unison for years, but I found myself wanting something that just worked invisibly with no admin effort so I switched to Resilio (Bittorrent Sync). Both work for my purposes. Anyone else try both of these and have feedback?

How difficult would it be to build a Dropbox clone on top of this?

What a fantastic tool!<p>A long time ago used unison to keep file uploads on 2x primary web servers[1] in sync. It worked like a charm. With IIS on Windows!

How does Unision compare to Rsync, is one a part of the other or both are different tools for syncing files?

Daily user since beginning of this year. Help keeps my laptop in sync with my remote dev environment.

Not to be confused with Panic&#x27;s Usenet&#x2F;NNTP client:<p>* <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Unison_(Usenet_client)" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Unison_(Usenet_client)</a>

Unison does not support hard links!