the difference being that, when i saw nuklear's README, i just wanted to learn enough C to be able to use it... with imgui the first reaction was (the first time i saw it), that i won't be able to use it for software targeting non-geeks. (and i really would like to have a good lightweight UI framework for C++!)

it might be just the screenshots, i've not tried any of both, but comparing the two README files, i cannot say that they are real alternatives.

even if -- very likely -- both are very good toolkits!

I do have font size issue with nuklear and imgui. The font size used in the nuklear extended example make it look fuzzy, especialy if I change the scale.

I tested the imGui and changing the code allowed to select a bigger font. I wished it was possible to change the widget look and feel because it looks minimalist.