Skype, in its free form, allows users of the Skype software to communicate with each other free of charge, and includes conference calling for up to five participants and cross-platform communication - the software is also available for Linux, Windows and Pocket PC platforms. Users can call ordinary telephone lines using Skype's pay service, called SkypeOut, which charges about $0,02 per minute.

Skype's features include a global Skype user directory, instant messaging, conference calling, log tracking, customisation, file transfer, the ability to sign in to your Skype account from anywhere where there is an Internet connection, encryption and more. Skype for Mac OS X requires Mac OS X v10.3 or newer, a G3/400MHz or faster processor, 20MB free hard disk space, microphone and 33,6kbps or faster Internet connection.