EchoLink

EchoLink is a closed source Windows program that allows communication over 2 meter radio by connecting radios and the Internet.

Why is there no source code for the clunky old Windows program?

ARRL page: https://www.arrl.org/echolink-irlp

EchoLink for Dummies http://www.ws6transam.org/Echolink_NE8K.pdf

Linux

See SVXLink and All Star Link

Mac

There is source code for the Mac version "EchoMac" https://sourceforge.net/projects/echomac/

It's old too.

Hardware

Node Ventures ClearNode https://www.node-ventures.com/

I think a couple of my rigs contain the hardware.

https://secure.echolink.org/interfaces.htm

https://secure.echolink.org/v71a.htm