There is a burgeoning market for Skype add-ons and tools that extend Skype's functionality or that leverage Skype's services. This is one of the most exciting aspects of Skype. By using Skype's Application Programming Interface (API), third-party developers are delivering neat add-ons—many of them free—that plug gaps in Skype's feature set, or just do something "completely different" (to borrow a phrase from Monty Python's Flying Circus). So, if there's a piece of functionality that you desperately need or want, chances are someone has had a similar idea and has built an add-on to satisfy that need or want. And if they haven't, Chapter 12 might just help you to hack your own!
Perhaps the first place to start looking for add-ons is Skype's own Extras Gallery, which is updated frequently and is located at http://share.skype.com/directory/.
Given the rapid pace at which all things to do with Skype are developing this chapter can only be a snapshot in time and a peek at what's available. Having said that, it is nevertheless a starting point that will help you to understand where to start looking for add-ons, how to hack and extend add-ons, and how to manage add-ons from a security perspective.
Broadly speaking, there are two types of Skype add-ons: hardware add-ons and software add-ons.
A Skype hardware add-on is not just, say, a pair of USB headphones. Such things are merely generic computer devices. ...