Monopoly means that there is only a single seller of a given commodity.
Windows was a monopoly in the 1990s and until I guess around when OS X came out - these alternative applications you mention didn't exist yet. Today I wouldn't say Windows is a monopoly, partly because good-enough alternative applications exists, partly because many (most) new, fancy applications are web-based and not limited to IE (as they once were). Today, really, there is really only one reason to run Windows, and it's Office - and that's going away fast, especially as users dawn on the fact that they can communicate without e-mailing Word documents around.
Another important component of Windows monopoly is exclusivity. Today I can trivially run Windows in a VM for that fraction of my workflow that isn't properly supported on Mac or Linux - 10 years ago, the best you could do was dual booting, which was painful and tricky for non-technical users.
Which brings me to Facebook: No, you can't port your social network lock, stock and barrel to a competing service. But you can trivially, with very little friction, maintain your presence on multiple networks - all you need is another tab in your browser, or a client app that supports each. You can even use the APIs of the respective services to integrate them with each other - you can automatically post Tweets to Facebook and vise versa. Plenty of people I know use both Facebook and Twitter in parallel with various degrees of automated integration. That's not the face of a monopoly.
The fact that other people don't want to stop using Facebook does not make Facebook a monopoly. They have strong network effects, yes, but that's not the same.
Monopoly means that there is only a single seller of a given commodity.
Windows was a monopoly in the 1990s and until I guess around when OS X came out - these alternative applications you mention didn't exist yet. Today I wouldn't say Windows is a monopoly, partly because good-enough alternative applications exists, partly because many (most) new, fancy applications are web-based and not limited to IE (as they once were). Today, really, there is really only one reason to run Windows, and it's Office - and that's going away fast, especially as users dawn on the fact that they can communicate without e-mailing Word documents around.
Another important component of Windows monopoly is exclusivity. Today I can trivially run Windows in a VM for that fraction of my workflow that isn't properly supported on Mac or Linux - 10 years ago, the best you could do was dual booting, which was painful and tricky for non-technical users.
Which brings me to Facebook: No, you can't port your social network lock, stock and barrel to a competing service. But you can trivially, with very little friction, maintain your presence on multiple networks - all you need is another tab in your browser, or a client app that supports each. You can even use the APIs of the respective services to integrate them with each other - you can automatically post Tweets to Facebook and vise versa. Plenty of people I know use both Facebook and Twitter in parallel with various degrees of automated integration. That's not the face of a monopoly.
The fact that other people don't want to stop using Facebook does not make Facebook a monopoly. They have strong network effects, yes, but that's not the same.