Skype

Skype is the world’s fastest-growing service for Internet
communication, allowing people everywhere to make unlimited voice and
video calls for free. Skype is available in 27 languages and is used in
almost every country around the world. Skype generates revenue through
its premium service offerings such as making and receiving calls to and
from landline and mobile phones, as well as voicemail and call
forwarding services. Skype also has a growing network of hardware and
software partners.