PSK31LX was the first PSK31 program written for Linux, and its
underlying PSK code is still used by many other clients.
PSJ31LX uses ncurses instead of a graphical interface. That
means you can run it in a terminal window. In fact, you don't
even need to have the X window system running. It will run fine
on a dumb terminal or a Linux system booted into single user mode.
The program comes with a sample psk31lx.ini file. You can copy
this to your home directory as .psk31lx.ini and make the
configuration match your system.
Versions after 1.2 require Pulseaudio.