I'm very wary about auto-updates that pull executables (as opposed to merely data) in this way. It's one thing for Chrome to do it, I assume Google does it in a way that's safe. But freeware/shareware projects? Not so much. Hell, who's to say the authors don't lose interest in two years and let the domain expire. I had one freeware or open-source app that didn't even have the courtesy of asking, it just pulled fresh binaries and restarted -- ouch. (At least you could disable this feature in the preference.)
So, if the server is hacked, or a DNS is spoofed, you cannot make auto-update pull broken/malware binaries.
The problem is that, if your update process is buggy in some release, you loose those users forever...
validating your updates via asymmetric crypto can be mildly expensive (http://www.verisign.com/code-signing/content-signing-certifi... lists Windows Authenticode certificates at $400/yr) but is within the realm of a small company.
setting up a Google-scale CDN and writing a reliable push update framework? that's the hard part.
It's open-source, cross-platform and very similar to µTorrent in both functionality and looks.
I think it is somewhat lighter resource-wise (I'm running it on my NAS), but apart from that I don't know the exact differences between Deluge and Transmission, but I thought I'd mention it for completeness' sake.
Deluge has all the features I want on a torrent client, I will replace my uTorrent installations on windows by deluge.
https://github.com/apankrat/assorted/blob/master/validate_pa...
Basically the idea is to get an Authenticode certificate and sign the update .exe with it. Then, when a program checks for an update and pulls it down, it would validate the package signature and will not proceed if the details - the application and the certificate subject names - are wrong. It is as simple as it gets.
