soft66 is a library and related command line tools for controlling the Soft66AD series of SDR receivers from Kazunori Miura JA7TDO. This enables users of these software-defined radio receivers to tune and use them under Linux. There is also a patch to enable support for this in Linrad.
cwwav takes one or more text files (or text read from standard input) and converts the text into an audio file (wav or mp3) containing the CW (Morse code) representation of the text. It's useful for generating practice files if you are learning CW and want to practice by listening to text. It's a very simple program but it is designed to do what it does well. That is, it is designed to produce good sounding CW output files, with proper timing and comfortable envelope to avoid keyclicks and to make the CW softer.
It's an excellent way to learn morse. There are plenty of fancy GUI programs out there, but none of them are as flexible as this command line program. I've gone from raw beginner to copying 12 WPM in 3 weeks just occasionally spending half an hour with this program, and had fun as well.