How do skype extensions for browsers work?

Question

We have plans to develop a web application that will be associated with our locally running application. One option is to use browser extensions. I studied how Skype add-ons for browsers interact with a Skype client. In Firefox, adding Skype adds an HTML snippet when it encounters a phone number. it

<span skypeaction="...">

handled by a Skype extension that makes a call using the Skype API? Extensions for other browsers use Skype API or other communication mechanism?

Answer 1

, . Skype, , Skype , . .

Answer 2

Skype , -, , , span .

span skype , skype.

iTunes IRC, irc://....