I suspect it depends on what "mature" means to you, but owncloud has been around for a little while now, and seems to be updated reasonably regularly. LDAP integration is beta, so it might not be suited to a corporate environment but, for home use, it has been fine for a while (2? 3? years now.)

There is a plug-in for it, which allows you to encrypt the files at rest within the server, but this did not work so well for me, as it never seemed to finish — I don't think I have a big archive, as it is only about 5GB, but they are mostly small documents (and so a lot of them), rather than images or video. Sync only via https can be forced as an option, which is great, and it works fine with self-generated certificates, after the usual "warning — do you want to trust this" dialogue on setup.

Since it uses a flat file structure on the server, no reason you could not rsync that to your chosen off-site storage as a cron job if you wanted, else there is a backup module which might do that for you anyway.

Not quite the same as BitTorrent Sync, but I have used owncloud for a while, as I prefer data to be on my infrastructure where possible. It was easy to set up, although was too slow on a Raspberry Pi to be useable, and I have not had much luck using the default sqlite. Now on a Debian VM with MySQL, and it's running just fine.

I would not make it publicly accessible, though, as it's just not worth the risk to me, so it only syncs when I am travelling after I have connected to the VPN. However, if you didn't have a static IP, a dynamic DNS service should do the job just fine of making it easily addressable externally.

Of those listed, the only one with which I have any experience is the Pi and, for OwnCloud, it was pretty awful. It did install, but owncloud ran incredibly slowly — I tried to tune the PHP installation, but I couldn't make enough of a difference to make it usable. I found much the same with wordpress.

A VM Debian image on a more robust server did the trick...

That would need one heck of a lot of marinade...

They certainly sell an adapter, but it is not supplied in the box, at least in my experience of devices bought from Apple stores in the UK.

... with the possibility of increasing the cap if needed.

I am in the UK and wanted to move to an ISP which offered FTTC, IPv6, a static IP, would be happy for me to run servers and would not implement CG-NAT, and offered good technical support in the event I should need it. The ISP which was most highly recommended to me based on those criteria offered FTTC for a fixed monthly price, with a cap — if paying a proportionate more-than-average-in-the-consumer-market price gave me a proportionate more-than-average-in-the-consumer-market service, that sounded like a good trade-off to me, even with a cap.

Coming from an uncapped connection, I was nervous about buying something with a cap, but, having checked our usage for a three month period, I picked the option with a cap three times that (guessing that a faster connection would mean we use it for me) and, so far, that has worked out well for me. If I want another 100GB, I can pay for that, either as a one-off, on a particularly heavy usage month, or to upgrade the connection permanently.

(The ISP is Andrews and Arnold and, so far, I have been more than happy with them. I guess that they have to pay upstream for capacity, and an unlimited connection would entail a pretty significant premium to ensure that they were not left out of pocket.)

I realised I was wasting far too much time on Facebook a couple of years ago, along with other forums, and found it hard not to browse there - often, I found that I was just typing the URL without thinking about it, and loading the site without giving it any thought. A friend recommended BlockSite to me, and, whilst I felt a bit stupid at needing this crutch, I took it, and managed to get things back under control.

Just add in the URLs of the site in question, and it blocks access to the pages (and elements at those URLs from loading as part of other pages). Editing a hosts file is probably just as suitable, but this worked for me...

What bright spark came up with the idea of this merger?

Perhaps we could have one charging company merge with another time after time after time, thereby doing it in series.

Two or three, maybe even four, times, perhaps — but if that's an extra $100 per year, or even per month, there would be a lot of days without the free pizza or soda?

Unless you are installing a production system in front of a room of people, and then not changing the password afterwards, just carry on as usual:

I used my old iPod with Amarok under Ubuntu for quite some time — I actually found it easier to use that iTunes on Windows, which, for me, crashed more often than it worked.