Fax applications are programs that can completely manage faxing of documents, and/or images. Fax applications have the ability to run in the background listening for incoming fax calls. In addition, Fax applications may allow the automation of sending and receiving faxes with limited interaction from the computer user. Fax applications can act as a full-duplex fax machine replacement if properly configured. Running a fax application may require an Internet connection or phone line connection to properly transmit and receive fax data.