Fldigi

Fldigi is a modem program which supports most of the digital modes used

by ham radio operators today. You can also use the program for

calibrating your sound card to WWV or doing a frequency measurement

test. The program also comes with a CW decoder. fldigi is written with

the help of the Fast Light Toolkit X GUI. Fldigi is a fast moving

project many added features with each update.

Flarq (Fast Light Automatic Repeat Request) is a file transfer

application that is based on the ARQ specification developed by Paul

Schmidt, K9PS. It is capable of transmitting and receiving frames of

ARQ data via fldigi.