There used to be a PKL app compatible with PortableApps, for defining and using your own keyboard layout setup. It also had some additional handy keyboard-related functionality like a so-called Extend layer for better navigation and editing.
Since 2014 I've built on its legacy and I'm still maintaining and developing the new EPKL app:
It's come a long way from its predecessor, adding lots of functionality and fixes. I'm quite proud of it.
I think it still adheres to the PortableApps format.
EPKL builds on the abandonware PKL source code, using compiled Autohotkey code. Releases contain the executable; should one wish to check out a commit, there is a compile.bat file that generates the executable.
Could my work of love make the PortableApps platform?