The free but proprietary Skype is a popular calling option.

This month we’ll show you some popular Linux tools for Internet telephony

Internet telephony does not need to be complicated. You can talk to the world with just Kphone, a normal sound card, and an account with an Internet phone provider.

When you want to call your friends in distant countries, don’t pick up the phone; just put on your headset and fire up Linphone.

An old computer is all you need to build your own do-it-yourself personal phone server.