Perhaps the most popular desktop VoIP communication tool, Skype 1.4 evolved from the controversial peer-to-peer technology that powers the Kazaa file-sharing application for Windows.
Skype is a highly refined VoIP application that is compatible with OS X, Windows, and Linux. It permits users to send text messages and make voice calls to other Skype users, as well as place computer-to-phone calls to traditional telephone numbers. The active Skype user community is said to number around six million simultaneous users at any given time. This is good, because it means you’re more likely to find your contact on the Skype network than on any other computer-to-computer calling system.
Skype’s efficiently designed user interface resembles that of a traditional IM application such as iChat or Yahoo Messenger: essentially, it’s a list of your contacts and a call history. You can access basic features, such as changing your status and placing calls to someone in your contact list, using a menu-bar icon that appears whenever Skype is running. If the Skype window is active, you just double-click on a contact’s name to place a call.
Like other VoIP calling tools, the Skype software is free. If you choose to call (or receive calls from) a traditional telephone number, you’ll pay per minute, using prepurchased credits called SkypeOut minutes. Skype also offers other premium features, including voice mail. This feature works more or less like traditional voice mail, answering your calls with a recorded greeting when you’re not around and capturing a voice message from the caller for you to retrieve later on. Skype offers conference calling too, so you can have a voice chat with as many as five participants at a time.
Derived from IM With its contact list, Skype looks a lot like a traditional IM application, such as iChat.
Once you become a Skype user, you can also obtain a SkypeIn number that users of traditional land-line and cell phones can reach you at. When they call this number, Skype connects calls to the Mac where you’ve logged on to your Skype account. This SkypeIn number could save you a lot of money on international long distance. If you are always receiving calls from family in, say, Poland, then you could get a Polish SkypeIn number to reduce the charges your family incurs by calling you. Skype offers SkypeIn numbers all over the world. Using Skype’s call-forwarding feature, you can easily forward your unanswered calls to another Skype user or to a phone number of your choosing.
The computer-to-computer calls offer extremely high-quality audio, thanks to Skype’s choice of a proprietary sound standard and a commercially licensed audio encoder. Skype also secures calls through a very strong encryption scheme, making it nearly impossible for would-be eavesdroppers to monitor your calls. It allows you to customize your ring tones, and it will even automatically pause a current iTunes track when you receive an incoming call.
Skype is well integrated with OS X. For example, you can use Skype’s Import function to populate your Skype contact list with the phone numbers in your Apple Address Book. Skype also supports AppleScript, so you can tie it into other applications to build specialized telephony functionality—for example, a FileMaker sales-contact database that automatically dials prospects on a predetermined callback schedule. Unfortunately, the Mac version of Skype does not support videoconferencing.
Macworld’s buying advice
Skype is a mature, reliable, and popular VoIP communications tool. Though the Mac version lacks video features, it offers unmatched sound quality, convenience, and ease of use. If you need a desktop VoIP tool that also allows you to dial traditional phones, there’s nothing better than Skype.
[ Ted Wallingford is the author of Switching to VoIP and VoIP Hacks (both O’Reilly, 2005) and an independent technology consultant based in Elyria, Ohio. He updates the Web site www.macvoip.com semiannually. ]