Small, portable, highly customizable SIP softphone for Windows.
Based on re/rem/baresip (https://github.com/baresip/).
Kiosk-like GUI made out of flat buttons
Kiosk-like application on a Lenovo tablet
Four video files playing on tSIP buttons with mpv plugin
Source code is using mostly BSD license (same as baresip).
Parts of the code might be using different but offering similar freedom (freedom to create closed source derivatives) licenses.
tSIP is built with Turbo C++ Explorer 2006 (free version of BDS 2006, aka C++ Builder).