Not being sarcastic, even - it's a pretty powerful approach that deserves better, unfortunately distribution of knowledge in Computing Science, especially historical knowledge if you never encountered it yourself, is pretty hard.
I pay homage to the Lisp community w/r/t programming interfaces in this post: https://amasad.me/disintegrated
There's some documentation about 'Commands' in CLIM II here for example: http://www.lispworks.com/documentation/lwu41/climuser/GUID_1...
Commands are first class objects which live in command tables and which CLIM can look at to generate bits of UI and allow parameters to be specified. Central to this in CLIM is the idea of presentations - where domain objects are 'presented' onto the screen and the link to the domain object is maintained. That way you can invoke a command on that object in various ways, for example you can type a command name and then click a presented object which is acceptable as a parameter.
The Symbolics S-packages used these concepts to make (I presume) powerful 3d modelling programs back in the day (I haven't used them): https://www.youtube.com/watch?v=gV5obrYaogU - sorry for the poor video quality.
https://twitter.com/rainerjoswig?lang=en (lispm on here) sometimes posts interesting things about Genera