XML Scripting to make controls?

I found this repository when looking around GitHub for XoJo stuff.

https://github.com/beardedio/XojoControls

These custom controls all seem to be made with XML markup. I dragged one of them into a test project and it seemed to work.

Is there a reference somewhere that explains how this works?

Thanks :slight_smile:

Look up external items in the User Guide. These items have been exported and saved as Xojo XML Code files.

Thanks @Wayne Golding