On the other hand as well, open source most certainly does not mean secure. I don't even have to argue to make this point, I merely have to point out Heartbleed or Shellshock.

As a business model open-source arrangements such as Red Hat or the countless Hadoop services show that you don't really need to lock down the source code to create a successful business around it.

With communications software, the costs a closed-sourced software with magical trust-us crypto getting fully compromised is incredibly high. If people can't trust their basic tools to be private, nor be able to verify it, than they can't assume any conversation they have is private. That's a scary world IMO.

This is particularly true for broken encryption more than the presence of memory exploitation such as Heartbleed or Shellshock.

Then there's another effect that I like - after the initial patch was released, the story went public, we got notified immediately, then we could discuss about what caused it and see the actual commits and who did it. Such a catastrophe can sink a company, therefore you never see such post mortems for proprietary stuff. And yes, even I as a developer cannot audit software for security, but the point is that I could hire somebody else to do that for me, like the Finnish company that discovered Heartbleed.

So yeah, there is no concrete proof that proprietary stuff is less or more secure than open source, but the point is that we'll never know, because nobody can know how secure something is without looking at the source code.

The reason both were found and had the absurd propaganda campaigns behind them as they did that are the only reason you can even name them to begin with, is precisely because the underlying software was free.

On the other hand, let's name drop another vulnerability and its exploit: SMBRelay. Took 7 years after it was made public to introduce an incomplete and partial fix. Still exploitable to this day, 13 years later.

- Skype is "everywhere" (Windows, Windows RT, Windows Phone, OS X, iOS, Android, Linux, FreeBSD, Blackberry, XBox One) and opposed to a handful of places (Windows, Linux, OS X, Android, iOS, FreeBSD, OpenIndiana). Plus Outlook.com's Skype implementation supports most platforms with a HTML5 browser.

- Landline/cellular phone calling. Text message sending.

- Caller ID, Voicemail, etc.

- Skype Numbers (i.e. buy a landline phone number people can call your Skype via, which is insanely useful for SMBs and individuals alike).

- Tox's feature list is largely a myth. Most clients are missing major Skype features and none support all of them, see this: https://wiki.tox.im/Clients#Features

People who think Tox is a Skype replacement aren't Skype's core demographic. The landline/cellular/etc functionality is heavily used by many and nothing that claims to be a replacement can be taken seriously if it lacks that.

You're making an assumption of guilt. The fact that something isn't open source doesn't inherently make it insecure.

I was thinking the same thing! But you seem to be assuming guilt and I am not. Honestly, I can see it both ways. It just seemed spurious to me to state that if we don't know it's good, it must be bad.