I came across this license:
Copyright © 2014, 2015, 2016 Philip Withnall philip.withnall(a)collabora.co.uk
Copying and distribution of this file, with or without modification, are
permitted in any medium without royalty provided the copyright notice
and this notice are preserved. This file is offered as-is, without any
(So it's part of the autoconf archive.)
It's free and seems similar to HPND in construction, but I don't
recognize the wording. Has it already got a separate tag?