I want to know something?
Who merges pull request in this repository? is linus? or others?
No one, it's not even sure this repo is linked to Linus. It seems to be just a copy of https://git.kernel.org/pub/scm/editors/uemacs/uemacs.git/
Does Linus use macros with uemacs?
I like the simplicity here, Jasspa's microemacs has similar simplicity together with tons of functionalities - ideally something like Jasspa could be further polished/developed ...
This is uEmacs/PK, an enhanced version of MicroEMACS 3.9e. So the macro/script engine is kind of outdated. Daniel Lawrence made significant changes to macro support of MicroEMACS until version 5.0, I believe Jasspa branched out of MicroEMACS at a later time than uEmacs/PK. The good thing about Jasspa is that they get approval from Daniel Lawrence to re-license from non commercial use to GPL, while uEmacs/PK (this repository) is kind of stuck in license limbo (probably still non commercial).