Skype is the king of the Voice Over IP (VOIP) world. It is one of those applications that really don't need an introduction. Although the application has changed a lot in the last few years, it still offers the best service for calls both over the Internet, landlines and to mobile phones.
Live Messenger (previously known as MSN Messenger) has been incorporated into this application, so when you log in with your MSN account you are given the chance to sync your Skype and MSN accounts, so you can chat with your contacts from a single window. Calls can also be made to MSN users. This makes a lot of sense after the purchase of Skype by Microsoft, and its integration with Xbox Live. So, this is perhaps the most important change to Skype since the last time that I reviewed the application.
Graphically, Skype still keeps the same look and feel. It has integrated other elements to its graphical user interface. For instance, now you can access social updates from your contacts by going to the Skype Home. This window shows all the status changes by your contacts in the last few days. You can also update your status from here.
A lot of performance updates have been made in the last three major versions of the app. There have been some problems with privacy regarding Skype, including the NSA debacle a couple of weeks ago, so keep in mind that all the calls and messages that you send using Skype might be monitored.